Unless the United States withdraws its military forces from Iraq in the near future, a war that began as an unnecessary invasion based on deception and predictably grew into a disastrous occupation will go down in history as a terrible crime, if it hasn’t already. For Americans of conscience, Iraq has therefore become the paramount moral issue of our time.

Those of us who were against the war even before it began were often disdained, but now, after four years, only the most myopic or callous among its many well-placed supporters can deny the catastrophic consequences. By inspiring legions of anti-American terrorists where there were few, by straining the US military to its breaking point, by alienating traditional and potential allies abroad, by frightening other states into acquiring new weapons and by provoking popular revulsion around the world, the war has undermined our real national security, from Russia, Afghanistan and the Middle East to the “Homeland.” And by already spending more than $400 billion, suffocating other policy initiatives and polarizing the nation, it has prevented the domestic reforms this country urgently needs.

But it is the war’s human costs that must be emphasized above all else. The Bush Administration and its bipartisan enablers have already squandered more than 3,100 American lives and maimed tens of thousands more for an unworthy and unwinnable military adventure whose declared purpose has changed repeatedly–from capturing Iraq’s (nonexistent) weapons of mass destruction, to fighting Al Qaeda, to deposing a tyrant, to spreading democracy and now to countering Iran. As a result, the families of those American victims have been left without even the solace of knowing their sacrifices were not in vain.

Still worse, all innocent life being equal, is the ongoing humanitarian catastrophe the US war and occupation have wrought in Iraq itself. Since 2003 that society has been decimated. Anywhere between 58,000 and 655,000 are estimated to have been killed, and a great many other bodies have been shattered, not to mention the thousands inhumanely imprisoned and mistreated; approximately 4 million have been driven in fear from their hometowns and villages, a figure increasing by 50,000 every month, about half of those out of the country; and much of its once modern social and economic infrastructures have been pounded into rubble. Among the major casualties is Iraq’s middle class, a prerequisite of stability, whose professions, prospects and notable religious tolerance have been all but destroyed, along with many mixed Shiite-Sunni marriages and extended families. “This,” lamented a young Iraqi, “is civilization gone backwards.” The US war is not solely responsible for these tragedies, but it made them possible.

All of these consequences grow steadily worse and will continue to do so, as every recent US intelligence report tells us. Indeed, events have become so horrific and undeniable that even long-complicit leading figures in both American political parties now speak of “withdrawal”–but, with very few exceptions, not actually a prompt, determined or complete withdrawal. Even at this late date, most of them are merely “symbolic” opponents of the war, content mustering just enough courage to resist the Administration’s proposed military “surge” or its hints of expanding the conflict to Iran.

These belated, halfhearted critics give various reasons for opposing a real end to the American occupation, reasons not entirely unlike the justifications given by the Bush Administration and its “withdrawal through victory” accomplices. None of their rationalizations, considering the ever-growing disaster, are compelling. In particular:

§ They warn that a near-term US exit would result in a failed Iraqi state, plunging that country into violent civil war and chaos and turning it into a “breeding ground” for terrorists. But that has already occurred because of the US invasion. No truly functioning state exists in Iraq today, only a pseudo-“sovereign” government whose effective authority does not extend far beyond its own offices in the Green Zone. Moreover, Iraq is already, by any criterion, in the throes of civil war, chaos and even ethnic cleansing (euphemistically called “sectarian violence”), while the US occupation has bred hordes of native terrorists since 2003 and become a bloody mecca for foreign ones.

§ It is added, in that connection, that an American withdrawal must await US-led regional diplomacy to stabilize Iraq and prepare the way for a larger Middle East settlement. But no amount of foreign diplomacy can stop the kind of zealous bloodletting rampant in Iraq. And even if it could, few if any of the Middle Eastern governments needed are likely to accommodate America in any meaningful ways while it is so brutally embedded in their region. Nor is this Administration likely to make the kind of concessions, especially to Iran, that might persuade them to do so. Truly productive multilateral diplomacy on larger issues in the area will be possible only when withdrawal has begun.

§ Apologists for prolonging the occupation also say that a US military departure would expand Iran’s influence and Iraq’s sectarian strife throughout the Middle East. But that too has already occurred because of Bush’s war. It is the four-year American military presence itself more than anything else that has both enhanced Tehran’s standing and spread new political and religious conflict in the region. Here too a US withdrawal is the first necessary step toward reversing those developments.

§ Finally, it is said America must “stay the course” because it has a “moral obligation” to the Iraqi people. But given the horrors unleashed on those people since the US invasion, the only moral course is withdrawal, along with a pledge to help fund the country’s reconstruction–a promise still unfulfilled despite $30 billion to $45 billion purportedly spent–if Iraq at last has an effective and peaceful government. It is true that an upsurge of violence may occur when the United States departs, but that will be so whether the departure is sooner or later, the essential difference being that many more people–Americans and Iraqis–will die in the interim. In reality, widespread killing in Iraq will never end until the US-led occupation ends and one side or the other in the civil war, deprived of foreign occupiers to provide resources or incite more enemies, finally prevails or both settle for a compromise. The Iraqi people seem to agree. In surveys taken last year, large majorities favored an immediate US withdrawal; and nearly 80 percent believed it would reduce the violence in their country.

Underlying these bipartisan excuses for staying in Iraq, indefinitely in effect, is the lingering illusion that some kind of American “victory” is still possible. Hence the self-serving assertions, particularly by the war’s early and unrepentant supporters across the political spectrum, that it was a good cause “botched” by the Bush Administration’s “shocking incompetence”; and hence their insistence that the occupation be given more time “to succeed” by providing the Washington-backed Iraqi regime with additional US troops and “benchmarks,” training more Iraqi forces (though the 300,000 already equipped haven’t helped), or by dividing the country into three parts, as though having failed to cope with one divided nation, the United States can do so with several antagonist ones.

Obscured by these rationalizations is the real lesson of the American-Iraqi tragedy: The United States does not have the right, wisdom or power to invade and occupy another country, still less an ancient civilization, with the ultimate purpose of redirecting that nation and its civilization. Such a mission will never result in any kind of victory, only the morally toxic political and humanitarian catastrophes we are witnessing and, if allowed to continue, crimes not soon forgotten or forgiven.

Principled opponents of the war must therefore be clear and unyielding on what an expeditious US withdrawal means, an essential issue also obscured by the Administration and its reticent critics. It means the removal from Iraq of all US troops and their equipment, as well as those Iraqi citizens who, fearing for their lives because they served the occupation, wish to leave. Once that decision is made, whether by the current Congress or an antiwar President, the US military will know how to implement it expeditiously, certainly within a few months. Meanwhile, all American troops in Iraq should be moved from offensive and other forward positions to strictly defensive ones in order to protect them and to reduce US complicity in the bloodletting. Here diplomats can help by negotiating with Iraq’s insurgent leaders and neighboring governments for a safe US exit and havens for Iraqis who must flee.

That kind of determined and complete withdrawal is now a moral imperative–the only way to begin redeeming our nation for its role in the death and destruction in Iraq. The time for political evasions and ambiguities on the part of leaders in both parties, especially would-be Presidents, is long past. Every month this war continues, more than 3,000 Iraqis and 100 Americans are likely to die, each new death further darkening the stain on America’s honor and on the conscience of its true patriots.