The following lecture was delivered by Andrea Peters, a member of the Socialist Equality Equality (US), at the Socialist Equality Party (US) International Summer School, held between August 2-9, 2025. It is the second part of a two-part lecture on how the GPU murdered Trotsky. The first part is available here. To accompany this and upcoming lectures, the WSWS is publishing “How the GPU Murdered Trotsky,” published in 1981, which contains documents from the first year of the Security and Fourth International investigation.

By July 1938 Stalin had assassinated multiple leading figures within the Fourth International, as part of a political genocide both within and outside the borders of the USSR. The aim was to secure the position of the bureaucracy by eliminating opposition and, above all, forestalling the prospect of world revolution—wiping out the human material that would, under the right historical conditions, make possible the seizure of power by the working class.

Despite Stalin’s terror, one individual remained whose existence was intolerable to him—Leon Trotsky. Co-leader with Lenin of October 1917, Trotsky personified world revolution. With his unyielding commitment to Marxism, egalitarianism, internationalism, and the working class, he embodied all that the bureaucracy opposed.

By the late 1930s, the revolutionary situation Stalin so feared had emerged. The world economy, not recovered from the Great Depression, was marred by conflicts over markets, resources, and colonies, currency and trade wars. The fascists were in power in Germany and Italy, the Stalinists’ betrayal of the German working class and Popular Front policies having disarmed the workers politically and materially and failed to block the rise of the far-right. Hitler’s war-waging intentions were clear. “The aim of German policy was,” he stated in a 1937 meeting with his top generals, “to make secure and to preserve the racial community and to enlarge it. It was therefore a question of space.”

Stalin had no answers to the crisis. He careened from one improvisation to the next. In August 1939, the Kremlin turned to a pact with the Nazis in a desperate attempt to shield itself from a war for which it was not prepared due to in large measure its destruction of the country’s revolutionary cadre.

But world war was coming and with it the prospect of the world revolution.

In his 2020 essay “Trotsky’s Last Year,” David North notes, “Driven into exile, deprived of citizenship by the Soviet Union and living on ‘a planet without a visa,’ lacking all access to conventional attributes of power, armed only with a pen, and dependent on the support of a relatively small number of persecuted comrades throughout the world, there was no man more feared than Trotsky by the powers that ruled the earth.”

In “Hitler-Stalin, Twin Stars,” written in November 1939, Trotsky related the following event:

On August 25, 1939, just before the break of diplomatic relations between France and Germany, the French ambassador Coulondre reported to G. Bonnet, Minister of Foreign Affairs, his dramatic interview with Adolf Hitler at 5:30 p.m.: “If I actually believed”—Coulondre told Hitler—“that we will be victorious, I also have the fear that as a result of the war there will be only one real victor—Mr. Trotsky.

Stalin too was terrified. The Soviet dictator, observed Trotsky’s biographer Isaac Deutscher,

could not bring himself to believe that his violence and terror had indeed accomplished all that he wanted, that the old Bolshevik Atlantis had really vanished.

He scrutinized the faces of the multitudes that acclaimed him, and he guessed what terrible hatred might be hidden in their adulation…

And even if the Fourth International was quite impotent now, who could say how the cataclysms of war might change the political landscape, what mountains they might not flatten and what hillocks they might not raise into mighty peaks?

Despite Stalin’s capacities for enormous violence, the Kremlin's hold on power was fragile and rooted in a contradiction.

Trotsky explained in 1940, “Stalin’s absolutism does not rest on the traditional authority of ‘divine grace,’ nor on ‘sacred’ and ‘inviolable’ private property but on the idea of communist equality. This deprives the oligarchy of a possibility of justifying its dictatorship with any kind of rational and persuasive arguments.”

As inequality worsened in the Soviet Union, so did the gap between the revolution’s promises and Stalinist reality. Thus, the bureaucracy bore a sociopathic hatred of Trotsky, his internationalism, and his “equality mongering” as it was called. They regarded him as a traitor. “The Moscow oligarchy’s hatred of me is engendered by its deep-rooted conviction that I ‘betrayed’ it,” Trotsky observed.

Notwithstanding his isolation in the late 1930s, Trotsky was still at the height of his powers. In “Trotsky’s Last Year,” North details the revolutionist’s astonishing output during the final period of his life. Trotsky intervened decisively against petty-bourgeois revisionist tendencies within the Fourth International, whose theoretical and political conceptions, if they had taken hold, would have paved the way for the liquidation of the movement.

In Defense of Marxism, Trotsky’s work that emerged from this struggle, clarified and preserved the theoretical and proletarian foundations of the Fourth International. Trotsky simultaneously provided strategic leadership in crucial discussions with the American Socialist Workers Party. He responded to every Stalinist slander. In Their Morals and Ours, he defended the right of the working class to make a revolution and exposed the bankruptcy of bourgeois morality. He returned repeatedly to the question of European and world war. In his unfinished “Bonapartism, Fascism, and War,” Trotsky analyzed the nature of the epoch, its politics, and its tasks. Above all, he fought to consolidate and build the Fourth International.

An initial attempt to assassinate Trotsky occurred in January 1938, about a month before Mark Zborowski organized Leon Sedov’s murder. Trotsky, who regularly received letters from supporters about GPU agents sent to Mexico via France and the United States, reports that an unknown man appeared at his residence with a forged message from a Mexican political figure.

“It was precisely after this incident, which alarmed my friends, that more serious defense measures were adopted: the establishment of a 24-hour guard, installment of an alarm system, etc.,” he explained in “Stalin Seeks My Death.”

In order for Stalin to kill Trotsky, dispatching assassins was not enough. The ground had to be prepared politically. In this, the West’s liberal “friends of the Soviet Union” did their part. The lies propagated in the Moscow Trials were lauded not just in presses of the Communist Parties, but in leading liberal American newspapers. The New York Time’s Pulitzer Prize-winning Russia reporter, Walter Duranty, wrote of the Moscow Trials in 1936, “It is inconceivable that a public trial of such men would be held unless the authorities had full proofs of their guilt.”

Mexican Communist Party newspapers accused Trotsky of leading an international espionage ring, conspiring to overthrow the government, and colluding with Franco. The following is a quote that Trotsky cites from one such outlet:

... As for the new pontiff, Leon XXX in view of the thirty pieces of silver of the dirtied Judas—he has carried out his role in the part elaborated for him by the Dies Committee ... Leon XXX intervenes in the affairs of Latin America on the side of the imperialist powers and completes his work declaring that ‘the oil expropriation was the work of the Communists.’

“People write like this,” observed Trotsky, “only when they are ready to change the pen for the machine-gun.”

In the spring of 1939, a Soviet agent approached the head of the Mexican Communist Party, Hernan Laborde. He demanded that his organization participate in the plot to eliminate Trotsky. Laborde, in consultation with other leading members of the Mexican Communist Party, determined this was too politically risky and, given Trotsky’s isolation, unnecessary. The GPU rejected this assessment. Laborde and two other leading figures appealed to Earl Browder, leader of the Communist Party of the United States (CPUSA), for support, but were unsuccessful.

In the fall of 1939, the Mexican CP’s National Committee called an extraordinary Congress for March 1940. Soon after the Congress was announced, Comintern delegates—actually GPU agents—arrived from Europe to oversee preparations. The envoys demanded the Congress agenda focus on “one essential point so as not to distract the attention of delegates,” specifically the “struggle against the enemies of the people (with the main theme being the struggle against Trotskyism…).” They insisted on a rigorous “house cleaning.” Trotskyists, other opponents, and possible critics of the assassination plot were purged.

During the latter part of the 1930s, the Soviet bureaucracy used Spain as a training ground for GPU assassins. In 1936, a civil war broke out in the country when fascist General Francisco Franco attempted a coup against the republican government. In response, workers in major cities armed themselves, formed defense committees, and appealed to rank-and-file soldiers for support. Through his actions, Franco had managed to provoke a workers’ uprising that threatened to defeat him and break the power of the Spanish bourgeoisie altogether. The consequences of such a victory would have been shattering for both the capitalists and the Stalinists.

The Kremlin, operating via the Communist Party in Spain, opposed the seizure of power by the working class. They disbanded its organizations, subordinated its militias to the capitalist state, betrayed workers on the battlefield, demanded an alliance with layers of the Spanish bourgeoisie, and killed Trotskyists, anarchists, and others who were not adequately loyal to Stalin.

To do this, the Stalinists cultivated a network of GPU agents in Spain schooled in techniques of political terror—repression, kidnapping, assassination, and organizational infiltration, which would be used against Trotskyists and ultimately Trotsky himself. Pavel Sudoplatov, the top-ranking Soviet foreign intelligence agent, who oversaw the operation to kill Trotsky, noted in his 1994 memoir, “Our subsequent intelligence initiatives all stemmed from contacts that we made and lessons that we learned in Spain. The Spanish republicans lost, but Stalin’s men and women won. When the Spanish civil war ended, there was no room left in the world for Trotsky.”

Around the time Trotsky was arriving in Mexico in January 1937, famous Mexican muralist and diehard Stalinist David Alfaro Siqueiros went to Spain to fight on the Stalinist side. There he was trained in guerrilla tactics and armed assault. Siqueiros returned to Mexico in 1939 as a GPU killer.

On May 24, 1940 at four o’clock in the morning, a team of assassins led by Siqueiros burst into Trotsky’s house in the Mexico City suburb of Coyoacan. They shot up Trotsky’s room and that of his grandson, nearly killing him, his wife, Natalia Sedova, and the 14-year-old Seva. At least 200 bullets were fired in Trotsky’s bedroom alone, with 70 holes found in just the walls.

Natalia saved Trotsky by pushing him between the bed and wall. Seva was shot in the foot. When the assassins retreated, the boy went looking someone to help, leaving a trail of blood on the ground where he walked. Trotsky described the most “tragic recollection” of that night to be when his grandson cried out for him. His fear, when he saw Seva’s bloody tracks, that the GPU had abducted the child was, he said, “the most painful moment of all.”

In addition to trying to kill the Trotsky family, the assassins threw incendiary devices in an effort to burn up the revolutionist’s papers. They sought, above all, to destroy Trotsky’s draft of his Stalin biography.

“Stalin feared,” explains North in “Trotsky’s Last Year,” “the consequences of Trotsky’s exposure of his background, his political mediocrity, his minor role in the history of the Bolshevik party prior to 1917 and during the Revolution, his incompetence during the Civil War, and, above all, the pattern of disloyalty and treachery that led Lenin to conclude in early 1923 that Stalin had to be removed from his post as general secretary.”

“How was it possible that Trotsky’s home was breached without an alarm being set off, without a shot being fired in return? The building’s structure and location should have made it easy to monitor the grounds inside the compound’s thick walls, observe what was going on in the immediate vicinity, prevent raids, and counter any attack.(p. 14).

But the breach was from the inside, not the outside.

Robert Sheldon Harte, an American SWP member and guard who was abducted during the May 24 attack and found weeks afterwards with two bullets in his head, opened the door for the Siqueiros gang.

Harte, it would later be discovered, was a GPU agent. There were some indications of this shortly after the assault. Stalin’s photo was reportedly found in Harte’s New York apartment and a Spanish-English dictionary signed by Siqueiros in his room in Mexico. When the Mexican police finally tracked down the location to which the assassins fled with Harte, eyewitnesses told them that the man was not held under lock and key. In 1995, when a trove of secret Soviet documents, the Venona papers, was released, Harte was confirmed to be a Stalinist agent.

Notably, Harte’s father, who arrived in Mexico immediately after his son was taken during the raid, was a friend of FBI head J. Edgar Hoover. The US Consulate in Mexico received instructions to give Harte senior all possible aid in his efforts to locate his son, given his relationship with the leading representative of the American political police.

At the time of the assassination attempt, Trotsky hesitated to conclude that Harte was an agent. But he did note, “it is, of course, impossible to consider as absolutely excluded the possibility that an isolated agent of the GPU could worm his way into the guard.” However, he added, “If contrary to all my suppositions such a participation should be confirmed, then it would change nothing essential in the character of the assault. With the aid of one of the members of the guard or without this aid, the GPU organized a conspiracy to kill me and burn my archives.”

The inside job of May 24, 1940 did not end with Harte. Once he opened the door and the Siqueiros team began shooting, Trotsky’s guards did not return fire. Their guns jammed. They had been loaded with the wrong ammunition by American SWP member Joseph Hansen, who was responsible for security at the house and maintaining the weapons. The Security and the Fourth International investigation would later determine that Hansen, who became a leader of the Pabloite movement, was a GPU agent and later worked with the FBI.

Outside the walls of Coyoacan, other Soviet assets were doing their part. The GPU knew virtually everything about the affairs of the SWP, which was tasked with Trotsky’s security. The secretary of the party’s leader, James Cannon, a woman by the name of Sylvia Caldwell, was one of their own.

When word of the assassination attempt broke, the Communist Party claimed it was a sort of false-flag operation, a “self-assault” intended to besmirch the Stalinists and glorify Trotsky. The absurdity of this did not stop it from being repeated by the “respectable” US press. Harry Block, writing in the leading American liberal magazine The Nation, described the attempt as a “put-up job.” The political attacks continued. The New York Herald Tribune claimed that Trotsky was organizing in collusion with Mexican general a “fascist regime south of the Rio Grande.”

The Communist Party press filled its pages with the “self-assault” accusation and its political leaders and representatives broadcast it. The police began putting pressure on Trotsky’s household. Two women who worked for him were taken to the station and made to sign statements, which the authorities claimed implicated Trotsky’s guards. Two of the guards were arrested, as well as two of Trotsky’s friends who had come by Coyoacan after the assault in order to offer support. The police gave them 15 minutes to confess.

In essays and statements written in May, June, and August 1940, including “Stalin Seeks My Death,” “The Comintern and the GPU,” a “Letter to the Mexican Attorney General,” and others, Trotsky explained the political motives behind the attack, exposed the role played by the Mexican Communist Party and the Comintern, and demonstrated the ludicrousness of the “self-assault” theory. He wrote in “Stalin Seeks My Death”:

What aim could I pursue in venturing on so monstrous, repugnant and dangerous an enterprise? No one has explained it to this day. It is hinted that I wanted to blacken Stalin and his GPU. But would another assault add anything at all to the reputation of a man who has destroyed an entire old generation of the Bolshevik party?

It is said that I want to prove the existence of the ‘Fifth Column.’ Why? What for? Besides. GPU agents are quite sufficient for the perpetration of an assault, there is no need of the mysterious Fifth Column. It is said that I wanted to create difficulties for the Mexican government. What possible motives could I have for creating difficulties for the only government that has been hospitable to me?

In a statement issued around the same time, Trotsky noted that the aim of the “self-assault” theory was, first, “to stir up police hostility against the victim of the aggression and thus to aid the aggressors” and second, “to cause, if possible, my expulsion from Mexico; that is to say, my transfer into the hands of the GPU.” In short, not having achieved their aims on May 24, the Stalinists hoped to use their failure to force the Mexican state to turn over Trotsky.

Trotsky, in his writings of this period, again took up the question of why Stalin had to try to kill him now, but could not previously. Trotsky wrote:

To the uninitiated, it may seem incomprehensible that Stalin’s clique should have first exiled me and then should attempt to kill me abroad. Wouldn’t it have been simpler to have shot me in Moscow as were so many others?

The explanation is this: In 1928 when I was expelled from the party and exiled to Central Asia it was still impossible even to talk not only about shooting but arrest. The generation together with whom I went through the October revolution and the Civil War was then still alive. The Political Bureau felt itself besieged from all sides…

In these conditions Stalin, after vacillating for one year, decided to resort to exile abroad as the lesser evil. He reasoned that Trotsky, isolated from the USSR, deprived of an apparatus and of material resources, would be powerless to undertake anything… Events have shown, however, that it is possible to participate in political life without possessing either an apparatus or material resources.

Trotsky warned another attack was coming. “The accidental failure of the assault so carefully and so ably prepared, is a serious blow to Stalin,” he explained. “The GPU must rehabilitate itself with Stalin. Stalin must demonstrate his power. A repetition of the attempt is inevitable.”

Sudoplatov reports in his memoir that Stalin followed all aspects of the efforts to murder his greatest opponent. When Siqueiros’s effort failed, he demanded the operation continue and viewed it as absolutely critical to the bureaucracy’s political survival.

Trotsky, following the official investigation into the May 24 assault, was anxious that the GPU network working to eliminate him be exposed. Without this, it could not be stopped.

In a diplomatically written letter to the Mexican attorney general three days after the May attack, Trotsky documented the Stalinists’ methods to set up networks of GPU agents in different countries. Without question, they existed in Mexico too. “It cannot be doubted in the least that the former and present chiefs of the Communist Party know who is the local director of the GPU … and that David Alfaro Siqueiros, who took part in the civil war in Spain as an active Stalinist, may also know who are the most important and active GPU members, Spanish, Mexican, and of other nationalities, who are arriving at different times in Mexico, especially via Paris.” He appealed for an interrogation of them.

In his article “The Comintern and the GPU,” Trotsky explained the relationship between the Stalinization of the workers international and the mortal threat to his movement. Once an organ of world revolution, the Comintern was now an appendage of the GPU. Through violent purges, the Kremlin had filled the international’s branches with loyalists and transformed its budget into a sluice for GPU money to sustain the police state’s operations, disseminate lies, and form alliances with sections of the bourgeoisie. He wrote:

The intervention of the GPU in the affairs of the Comintern, the system of bribery and corruption of the leaders of the labor movement in countries abroad began to develop systematically at the beginning of 1926 when Stalin placed himself definitively at the head of the Comintern.

At the same time, the irreconcilable struggle of the opposition (the ‘Trotskyists’) began against the arbitrariness and bribery of the Comintern and its periphery. Thus, for example, the opposition disclosed that Purcell, the well-known leader of the British trade unions, received in return for his “friendship” to the Soviet Union, i.e., the Kremlin, a secret salary of twenty-five pounds a month.

All sorts of material boons were likewise enjoyed by other prominent leaders of the same trade unions. Their wives received “inoffensive” gifts of gold and platinum. Needless to say, all these gentlemen and ladies, who did not formally belong to the Comintern, considered the Trotskyists as “traitors.”

In June 1940, as he was elaborating the political perspective and strategy for his defense and security, Trotsky turned again to the question of the world situation, Stalin, and the fate of the Soviet Union. He wrote:

In spite of the Kremlin’s territorial seizures, the international position of the USSR is worsened in the extreme. The Polish buffer disappeared. The Rumanian buffer will disappear tomorrow. Mighty Germany, the master of Europe, acquires a common frontier with the USSR… Her victories in the West are only preparation for a gigantic move toward the East … in his coming march against the USSR, Hitler will find support in Japan.

The agents of the Kremlin begin to speak once more about the alliance of the democracies against the fascist aggressors. It is possible that as the cheated cheater, Stalin will be forced to make a new turn in his foreign politics. But woe to the people if they again trust the dishonest agents of the Kremlin’s chief!…

Only the overthrow of the Moscow totalitarian clique, only the regeneration of Soviet democracy can unleash the forces of the Soviet peoples for the fight against the inevitable and fast approaching blow from imperialist Germany...

Almost exactly one year after Trotsky wrote these lines, Hitler invaded the Soviet Union. By the end of the war, 27 million Soviet people were dead. With his extraordinary capacity to foresee, to warn, there was no greater danger to Stalin than Trotsky.

On August 20, the GPU tried again.

In 1938, it dispatched an agent who had already infiltrated the American section of the Trotskyist movement to France. There, Sylvia Ageloff inserted herself into the work of the Fourth International’s French section and struck up a romance with another GPU agent, Jacques Mornard. Creating the fiction of a woman swept off her feet by a dashing, well-to-do European, Ageloff helped Mornard start to orbit around the Trotskyist movement without him ever having to take on the burden of membership and pretending to know anything.

Another lecturer will be going into further details regarding Ageloff, but the central point with regards to Trotsky’s murder is that Ageloff’s lover was the man who would kill Trotsky.

In early 1940, Ageloff and Mornard—who was now using the name Frank Jacson—made their way, via New York, to Mexico City. There, she got him access to the Trotsky household. Having been active in the efforts of the French section in the late 1930s and with a sister who served as a secretary and translator for Trotsky, Ageloff became a regular visitor to the house in Coyoacan.

While Jacson initially kept his distance, in late May, after the first assassination attempt failed, he began to make occasional appearances at the Trotsky home under the auspices that he was Sylvia Ageloff’s fiancé/husband. Jacson portrayed himself as a largely apolitical but magnanimous, moneyed man involved in international business. He was happy to do a kindness here and there for members of Trotsky’s household, thereby ingratiating himself to those who lived with the revolutionary and establishing himself as a visitor to be admitted to the home.

There were signs that Jacson was not who he claimed to be. He could never give a full account of the work he did and for whom, but had money and time. He traveled on a false passport. When asked for the location of his firm, he gave an office number that did not exist. Once, standing in the courtyard with Trotsky and Hansen while they were surveying efforts to fortify the house’s walls, Jacson remarked, “The GPU will use different methods next time.” 

But with Ageloff as an alibi, Jacson continued to present himself at the Trotsky home. He was good at name dropping, mentioning this or that Trotskyist when speaking with guards, brought gifts for Natalia, and made casual references to his party donations. He knew the restaurants and bars of Mexico City and invited others to join him, using the pressures that weighed on comrades to deepen his infiltration. Historian Bertrand Patenaude reported in his Trotsky biography that Cannon and Farrell Dobbs had an evening out with Jacson on June 11, 1940.

As the summer unfolded, Trotsky became suspicious of Jacson. He was offput by his boasting of his wealthy boss and stock exchange successes. He told Natalia that Jacson’s employer should be looked into, perhaps he was “some sort of fascist type.” “It might be better for us not to receive Sylvia’s husband anymore,” he said.

Mexican journalist Eduardo Tellez Vargas, who spoke on numerous occasions with Trotsky in the lead-up to his murder, told David North in 1976:

There came a moment when Trotsky trusted absolutely nobody. He trusted in no one. He didn’t specify or name names, but he did say to me: ‘I will be killed either by one of them in here or by one of my friends from the outside, by someone who has access to the house. Because Stalin cannot spare my life.’

Despite Trotsky’s concerns about Jacson, he was admitted to the house on August 17. Jacson claimed he had written an article against Burnham and Shachtman and wished for Trotsky’s input. In reality, this was a dress rehearsal.

Trotsky met with Jacson in his study, but sensed something was wrong. Jacson, allegedly raised in France, did not remove his hat while indoors and crudely positioned himself on the edge of Trotsky’s desk as the latter was sitting down to review his “article,” thereby standing over his host’s head. No doubt, this was Mercader trying to figure out the best way to position himself when it came time to strike a blow.

Coming out of this meeting, Trotsky told Natalia that he sensed an impostor and did not wish to see Jacson anymore.

He was right. In reality, Frank Jacson was Ramon Mercader, a Spanish Communist Party member and the son of Caridad Mercader. The mother Mercader, born to a wealthy Cuban family and married to a well-to-do Catalonian, was a fanatical Stalinist and GPU spy who did the Communist Party’s dirty work in Spain. She worked closely with the Soviet agent charged with directing the Trotsky kill team. Caridad recruited her son and arranged for him to go to Moscow for training as an assassin in the late 1930s.

On August 20, 1940, Mercader carried out his commission. Around five o’clock in the evening, Jacson was admitted to the household, the door opened for him by Joseph Hansen. He was not searched.

Jacson said he had come so that Trotsky could review a second draft of his article. Trotsky was unenthused and took his time making his way to his office from the courtyard where he had been tending to his rabbits. Mercader looked unwell and was, as he had been three days prior, clutching a rain coat on a warm, cloudless day. Trotsky remarked that he ought to look after his health.

Eventually heading to his study with Mercader, Trotsky seated himself at his desk to review the man’s article. Mercader then attacked him, plunging an alpenstock into his skull. Trotsky cried out and lunged at his assaulter, throwing whatever objects he could grasp to stop another blow.

Harold Robins, the captain of Trotsky’s guard, came running. The first to appear at the scene, he pinned down Mercader and began pistol whipping him. Trotsky stumbled towards the doorway, where, after leaning against the frame, he was aided by Natalia to a mat on the floor. He retained consciousness for a couple of hours and spoke in fits in and starts. Trotsky said it was the GPU, possibly aided by the Gestapo. He told Natalia he loved her. He asked that she, not the nurses, undress him in preparation for surgery. He told his guards, “He must not be killed—he must be made to talk.” The SWP failed to fulfill the second part of this instruction.

Trotsky underwent brain surgery the night of August 20, but died the following day.

Earlier that year, Trotsky had penned his final testament. He requested it be made public upon his death, but the full text was not released for several decades. He wrote:

I have no need to refute here once again the stupid and vile slander of Stalin and his agents: there is not a single spot on my revolutionary honor. I have never entered, either directly or indirectly, into any behind-the-scenes agreements or even negotiations with the enemies of the working class.

Thousands of Stalin’s opponents have fallen victims of similar false accusations. The new revolutionary generations will rehabilitate their political honor and deal with the Kremlin executioners according to their desserts…

For forty-three years of my conscious life I have remained a revolutionist; for forty-two of them I have fought under the banner of Marxism. If I had to begin all over again, I would of course try to avoid this or that mistake, but the main course of my life would remain unchanged. I shall die a proletarian revolutionist, a Marxist, a dialectical materialist, and consequently, an irreconcilable atheist.

My faith in the communist future of mankind is not less ardent, indeed it is firmer today than it was in the days of my youth…

Life is beautiful. Let the future generations cleanse it of all evil, oppression, and violence, and enjoy it to the full.

The day following his death, Trotsky’s coffin was borne through the streets of Mexico City. Crowds lined the sidewalks. Three hundred thousand people filed past his body as it lay in state for five days. Cremated on August 27, his remains were buried on the grounds at Coyoacan. The American government refused to grant the SWP a visa for the man’s ashes.

What happened to the GPU’s assassins?

David Alfaro Siqueiros, the leader of the first assassination attempt, was caught and charged, but served just a few months in prison. Released, he went to Chile to paint murals, invited there by the famous Chilean poet Pablo Neruda, who sponsored his visa and hosted the assassin in his home.

Frank Jacson was arrested, charged, and imprisoned. He never revealed his true name or admitted to being a GPU agent. He claimed that he was a disillusioned Trotskyist, driven to murder Trotsky out of political disappointment because Trotsky demanded he go to Russia to “organize there a series of attempts against different persons and in the first place against Stalin.”  

Trotsky, alleged Jacson, was a man “who desired nothing more than to satisfy his needs” and “who did not utilize the workers struggle for anything more than a means of hiding his own paltriness and despicable calculations.” The revolutionist’s opposition to his marriage to Sylvia Ageloff aggravated his rage, he claimed. Even in his confession, Jacson aimed to use his crime to further Stalin’s aims.

Jacson’s true identity as Ramon Mercader and the son of the GPU agent Caridad Mercader was not established for another 10 years. Spanish Communist Party exiles in Mexico knew who he was, but remained silent.

In 1947, Julian Gorkin, a leader of the Spanish POUM, who was in Mexico when Trotsky was killed, identified Trotsky’s assassin as the son of Caridad Mercader in the book Murder in Mexico. However, he did not know his name.

It took criminologist Dr. Alfonso Quiroz Cuaron until 1950 to definitively establish who Jacson was, information that he tracked down through discussions with Spanish police officials. When David North asked Cuaron in 1976 why it took so long, he replied, “No one was interested in establishing his identity.”

During this conversation, Cuaron revealed that it was not just Mercader’s identity in which no one was interested. They were not interested in him at all. When North asked him, “But have the Trotskyists never asked you questions on a purely professional level? About what happened, who Mercader was?” He replied: “No, never.”

Few understood Mercader’s psychology better than Cuaron, who had studied him closely for months before assessing his parole eligibility in 1955. Cuaron told North: “He was not sick, not abnormal. He was a fanatic—ideologically in love with the USSR.”

Cuaron’s parole report described Mercader as a “mythomaniac,” “inveterate liar,” “bourgeois in character” with “superficial knowledge of communism” who was “fully conscious of his action” and a “highly dangerous criminal.” Mercader never repented for his crime, he reported.

The criminal psychologist also suspected he had committed other murders. When asked by North if Mercader might have been involved in the killing and dismemberment of Rudolf Klement, Cuaron replied that the man was “perfectly capable of such an act.”

In 1960, Mercader was released. The Soviet bureaucracy ferried him, via Cuba, to Prague and then arranged for his move to the Soviet Union. Over the course of those years, he worked with the exiled Spanish Communist Party, held a position at a KGB spy-training school, went on vacations in the USSR and beyond, and received the Order of Lenin for his services.

Eventually, Mercader returned to Cuba. When the assassin was in the hospital ill with cancer, Fidel Castro visited him repeatedly. Mercader died in 1978. Joseph Hansen’s and the Pabloites’ support for Castro should be considered in light of this fact.

In an interview with David North in 1976, Mercader’s Mexican attorney reported that Mercader ultimately regretted his actions for the following reason: “[He] saw that the killing of Trotsky hadn’t finished off Trotskyism, that he hadn’t achieved his objective of making Trotskyism disappear.”

The SWP did not conduct a sustained investigation into Trotsky’s assassination. In late 1940, party attorney and leading member Albert Goldman wrote “The Assassination of Leon Trotsky: The Proofs of Stalin’s Guilt,” which dissected Mercader’s phony confession and made clear that, politically, it was without question that Stalin ordered the murder. Beyond that, nothing was done.

Sylvia Ageloff, whom the Mexican government jailed as an accomplice in the murder, was let go by the authorities for unclear reasons and traveled back to New York City in December 1940. There she issued a press release asserting her innocence. Apparently, the SWP accepted it. All of the questions related to her and how Jacson carried out one of the worst crimes of the 20th century were unexamined.

In his September 1940 address to the first SWP national plenum after Trotsky’s assassination, Cannon outlined the revolutionary tasks facing the movement, with world war approaching. He addressed the dangers of adapting to trade unionism. He insisted that the petty bourgeois revisionists, with their “howls” about the party’s “bureaucratism,” were in reality opposed to democratic centralism and a proletarian orientation. Pointing to the “GPU’s murderous killing machine, he stated:

[W]e have to check up on carelessness. We want to know who is who in the party. We don’t want to have any universal spy hunts, because that is worse than the disease it tries to cure. Comrade Trotsky said many times that mutual suspicion among comrades can greatly demoralize a movement.

On the other hand, there is a certain carelessness in the movement as a hangover from the past. We haven’t probed deeply enough into the past of people even in leading positions—where they came from, how they live, whom they are married to, etc.

Whenever in the past such questions—elementary for a revolutionary organization—were raised, the petty-bourgeois opposition would cry, ‘My God, you are invading the private lives of comrades!’

Yes, that is precisely what we were doing, or more correctly, threatening to do—nothing ever came of it in the past. If we had checked up on such matters a little more carefully we might have prevented some bad things in the days gone by.

But the political pressures on the SWP in the early 1940s were immense. In 1941, the American state used the Smith Act to charge the entire leadership of the party, minus Joseph Hansen, with advocating the overthrow of the government. Eighteen SWP members, including Cannon, were given prison terms of between 12 and 16 months. In the aftermath of World War II, as is reviewed in detail in the seminal work on party history, The Heritage We Defend, the SWP began to come under political and class pressures stemming from the restabilization of world capitalism.

Had the party pursued a serious investigation at any point after the assassination, they may have exposed not just the penetration of the US section by the GPU, but the network of agents operating across the Americas and elsewhere, whose dirty work no doubt did not stop in 1940.

The American section’s failure to investigate the assassination allowed state agents to continue operating in their midst. Zborowski was one of them.

In 1941, Lola Dallin, the woman who helped Zborowski get close to Sedov and dispel suspicions about him, facilitated Zborowski’s move to the US. Lola and her husband David supported him with money and accommodations. Eventually, he lived in the same building. In the early-mid 1940s, Zborowski continued to meet with SWP members, including Jean van Heijenoort, a leading figure within the American section and once Trotsky’s bodyguard, secretary, and translator.

In 1955, Zborowski was exposed as an agent, a fact revealed not by the SWP’s efforts, but by an article in the liberal magazine The New Leader. Zborowski, who was launching a successful career as an anthropologist, was left alone by the US government until 1958, when he was indicted for perjury. During his trial, he acknowledged his GPU spy activity, but not his role in the murder of Sedov. He was sentenced to four years in prison, but did not complete the term and eventually moved to San Francisco, where he secured prestigious academic positions.

Lola Dallin claimed that she did not know Zborowski was an agent until 1955.

The Dallins’ contact with state agencies, however, did not stop with GPU agent Zborowski. It has now been established that David Dallin, whom we suspected at the time of the Security and the Fourth International investigation of having ties to the US state, was an American asset. After World War II, in collaboration with other former Mensheviks turned anti-Bolsheviks, he went to prisoner of war camps in Europe to recruit anti-Soviet Russian fascists to the OSS, the forerunner of the CIA. US military intelligence suspected at the time that Dallin might also be a Soviet spy.

In 1975, Harold Robins, the captain of Trotsky’s guard in Mexico, courageously issued an open letter to the SWP, published under the title “Security at Coyoacan.” Robins enthusiastically supported the Security and the Fourth International investigation, providing key information to the party about what happened at Coyoacan and opposing all those who denounced the investigation.

In his statement, Robins observed that the assassination of Trotsky was an effort to resolve the crisis of leadership in the interests of the Stalinist bureaucracy. Indeed, with the murder of the greatest strategist of world socialist revolution, the forces of reaction delivered a might blow, one that revealed the vulnerabilities of the Fourth International to infiltration, state repression, and internal betrayal.

But Trotsky’s immense theoretical and political contribution could not be stamped out, and the crisis of leadership could not be solved in the interests of the Stalinists for all time by way of violence and intrigue. The ICFI has preserved the continuity of Marxism, and in this the Security and the Fourth International investigation has played a decisive role.