Democratic presidential candidate Barack Obama and his Republican rival John McCain walked side by side down the ramp into the pit where the World Trade Center once stood Tuesday in what was promoted as a demonstration of national unity on the seventh anniversary of the September 11 attacks.

The symbolic gesture followed a week of bitter attacks by the Republican campaign against Obama, including a lying ad charging that he had promoted “comprehensive sex education” for kindergarten students, and a ludicrous controversy—amplified and endlessly repeated by the media—over whether the Democratic candidate’s use of the words “lipstick on a pig” constituted a sexist smear.

The appearance of the two big business candidates at the site where some 2,700 died will do nothing to assuage the enduring grief of those who lost children, parents, spouses and loved ones seven years ago. Nor will it do anything to further the rebuilding of the area, which, after all of this time, remains a gaping hole in the ground, with neither new buildings erected nor any memorial erected to those who perished.

What the appearance was meant to bolster is the fading pretense that the 9/11 attacks are a common touchstone of national unity. This was always a hollow myth propagated by the ruling establishment and the corporate media. Before the dust had settled from the collapsed twin towers, the stark class divisions, the corruption and parasitism that pervade American capitalism made themselves felt in this catastrophe, just as they do in every other facet of social life.

While hundreds of firefighters and other emergency service workers gave their lives in an attempt to rescue people from the towers-and thousands of others sacrificed their health in an attempt to recover the dead—the top financiers on Wall Street used the occasion to further enrich themselves, grabbing hundreds of millions worth of stock options at fire-sale prices after the attacks forced the markets to close.

New York’s Republican Mayor Rudy Giuliani attempted to parlay the catastrophe into a national political career, casting himself as “America’s mayor” and the hero of 9/11. The firefighters who had seen 343 of their comrades die that day, however, blamed him for the shady deals that left those in the towers without radios capable of receiving orders to evacuate the shattered buildings.

The real content of the myth of national unity promoted in the aftermath of the terrorist attacks was the attempt to manufacture popular support for war abroad and repression at home. This is the cause to which both candidates leant themselves to again on Thursday.

Obama issued a statement for the occasion, expressing thanks to “the Americans defending us every day in our communities at home, and in our military abroad.” He called on the American people to “remember that the terrorists responsible for 9/11 are still at large and must be brought to justice” and vowed to “defeat terrorist networks” and “defend the American homeland.”

McCain, meanwhile, used the occasion to deliver a speech at the memorial service in Shanksville, Pennsylvania, where hijacked United Flight 93 crashed on September 11. Pennsylvania is among the most hotly contested states in the presidential election.

In the evening, both candidates participated—separately—in a forum on “national service” held at Columbia University in New York City.

For most of the past seven years, the American people have been subjected to government propaganda that has systematically attempted to intimidate them with the supposedly omnipresent threat of terrorism. The unending refrain has been that, without wars of aggression, domestic spying, torture, extraordinary rendition and the evisceration of the US Constitution, there would be “another September 11” or worse.

Recent polls have indicated that this relentless campaign of fear is producing diminishing returns. While in 2002 and 2004, fully a quarter of those surveyed in the US described terrorism or national security as the number one problem confronting the country, that share fell to 16 percent in 2006 and, in the current election year, has plummeted to 4 percent.

Media reports have attributed this decline largely to passage of time since the tragic events of seven years ago. It is an “issue that has lost prominence for American voters as the deadly attacks recede in the public memory,” the Washington Post asserted.

However, far more powerful forces have been at work on mass consciousness than merely fading memories.

First there are the wars in Afghanistan and Iraq that the government used September 11 to promote, which have become deeply unpopular. Then there is the real economic terror that has been unleashed against broad masses of working people, who are now facing the loss of both their jobs and their homes, as the unemployment rate has risen to the highest level in more than five years and home foreclosures have set a new record.

Finally, there is 9/11 itself, which remains an event shrouded in mystery. To this day, there has not been a single genuinely independent investigation of what was worst single loss of civilian life on American soil. Nor has anyone in the US government ever been held accountable for what was at the very least the most egregious failure of US security and intelligence agencies in history.

What is indisputable is that the terrorist organization that is blamed for the attack was led by individuals—including Osama bin Laden—who had earlier been counted among Washington’s allies and the CIA’s “assets” in a US-funded effort to overturn a Soviet-backed regime in Afghanistan.

Moreover, there is ample evidence that those who carried out the hijackings seven years ago included individuals who were well known to US intelligence agencies and whose movements were carefully tracked. Yet, they were allowed into the country and even permitted to renew their visas.

The apparent high-level protection enjoyed by these individuals strongly suggests that there were those in the US government who knew that a terrorist act of some kind was being prepared and decided that it would prove politically useful to allow it to happen.

The events of 9/11 were not the cause of the eruption of American militarism that followed, but rather the pretext for this violent shift in US foreign policy. They provided a propaganda justification for the launching of long-planned military interventions aimed at asserting US hegemony over the energy-rich regions of Central Asia and the Persian Gulf. In this effort, the Bush administration enjoyed the full support of the Democratic Party.

The World Socialist Web Site warned that this was Washington’s aim within days of the attacks.

“The attacks on the World Trade Center and the Pentagon have been seized on as an opportunity to implement a far-reaching agenda for which the most right-wing elements in the ruling elite have been clamoring for years,” the WSWS warned on September 14, 2001. “Within a day of the attack, before any light had been shed on the source of the assault or the dimensions of the plot, the government and the media had launched a coordinated campaign to declare that America was at war and the American people had to accept all the consequences of wartime existence.”

The shoulder-to-shoulder walk down the ramp into the pit at New York’s “Ground Zero” by Obama and McCain only serves to demonstrate that the militarist policy initiated on the false pretense of avenging the dead of 9/11 retains the bipartisan support of America’s ruling elite.

Both parties continue to promote the fundamental conception that the US remains engaged in a “global war on terrorism” which justifies military aggression abroad and political repression at home.

There are tactical differences to be sure. Obama has criticized the Bush administration and Republican candidate McCain not for their support for war in general, but rather for what he charges is the over-concentration of US military power in Iraq at the expense of the American intervention in Afghanistan and Pakistan, which he presents as the “real central front” in the so-called war on terror.

McCain has charged Obama with seeking “failure in Iraq” by proposing a timetable for the withdrawal of US combat troops.

However, as the Los Angeles Times noted Thursday, “Beneath the harsh rhetoric, the two candidates—who meet today in New York City to commemorate the seventh anniversary of the Sept. 11 attacks—seem to be moving toward consensus on their broad-brush strategies.”

The newspaper went on to quote Brian Michael Jenkins, described as a “leading authority on terrorism” at the Rand Corp. “The process of political campaigning has exaggerated the differences of the two candidates on trivial issues,” said Jenkins. “But when it comes to where the campaigns have outlined their platforms on Iraq, Afghanistan and national security, there isn’t a great deal of difference.”

In other words, both candidates support policies that translate into the protracted occupation of Iraq—albeit, if possible, with fewer ground troops—an escalation of the war in Afghanistan and its extension across the border into Pakistan and the continuation of domestic spying and other forms of political repression in the US itself.

And, as the display of “unity” on September 11 indicated, both are determined to continue promoting a global “war on terror” as the pretext for the use of military power in pursuit of US global hegemony, a policy that threatens new and even bloodier wars to come.

Under these conditions, mass opposition to militarism can find no viable political expression through either of the two corporate-controlled parties. The struggle against war and the fight to defend living standards and basic democratic rights cannot be waged outside of an irrevocable break with the Democratic Party and the building of a new independent political movement of the working class based on a socialist program.