Watching the Senate Armed Services and the Foreign Relations Committees question Iraq proconsul General David Petraeus about the status of the war was a disturbing, almost embarrassing, experience.

It was as if the unspoken but acrid truth that this war was a huge mistake and a terrible waste had so permeated every crevice of Capitol Hill that the air in the hearing room was noxious with futility.

The so-called surge on which Petraeus reported has been a narrowly defined success. Casualties among American troops and Iraqi civilians are down since January 2007, when the surge was announced, as are insurgent attacks. The seizure of weapons has dramatically increased.

But when all the bodies are counted, the level of violence continues at a pitch that was anxiety-provoking two years ago. Within the context of a conflict that has lasted longer than World War II, that must be as sobering to hawks as it is depressing to doves.

During the first of two day-long hearings, the anti-war senators were careful to reaffirm their solicitude for American troops. The pro-war senators were cautious not to challenge the underlying rational for President Bush’s adventure. Nuance was all.

Given that Bush has guaranteed the war will continue more or less as it has well into the first year or two of a new presidency, the Petraeus hearings made for a hollow exercise in accountability.

The three presidential candidates provided what drama there was. They temporarily quit the campaign tour to return to their day jobs, as if to audition for the job of commander in chief. They played in character.

John McCain exhibited a flash of lucidity when he referred to past incompetence by this administration. But he neutralized his affect with one of his increasingly occurring senior moments, once again confusing the Sunni with the Shia — or was it the Shia with the Sunni? Never mind.

Hillary Clinton was solid and, well, competent. Clinton’s observation that Petraeus’s cautious, guarded, and almost defensive report of progress required a “willful suspension of disbelief” was the closest to confrontation that the day came.

Within the narrow range the candidates allowed themselves, Barack Obama provided the shock of recognition. Obama’s exchange with Petraeus crystallized the futility that is Iraq. Obama talked about the “endpoint” and asked how America could define “success,” which, in the managerial idiom of the modern military, is what was once known as victory.

Neither Petraeus nor his diplomatic sidekick, Ambassador Ryan Crocker, could provide a soothing, let alone acceptable, answer.

Even under different circumstances, the concept of victory in a limited war such as Iraq would be elusive; the realities of time and place resist (perhaps subvert) popular conceptions of even tragic heroism.

The United States, for all its power and might, is a captive nation, a prisoner of a weak and unreliable Iraqi government and unpredictable Iraqi insurgents.

Those insurgents, of course, not only oppose the central government, but constitute warring factions in a once-boiling civil war that has now been reduced to a constant simmer, subject to occasional flare-ups.

America is a caught in a quagmire. That sinkhole is a physical reality for US troops in Iraq who live with it day after punishing day.

Because of the schizophrenic nature of Bush’s leadership, the might the US needs to wage war — should the need arise elsewhere in the world — is steadily atrophying.

A week before Petraeus was sworn in to testify, Army and Marine commanders warned, again, that the wars in Iraq and Afghanistan have reduced military readiness to its lowest point in memory. Those wars and the constant tours of duty they require, together with insufficient recovery time for those posted to combat, is also eroding the mental health of American troops, who — according to military experts — are showing alarming signs of anxiety, depression, and stress.

If the Petraeus hearing demonstrated anything, it is that the first step, the necessary step, to escaping the Iraq quagmire is to recognize it for what it is. Despite overwhelming opposition to the war, the rules of political engagement have either not caught up with public opinion, or are not yet elastic enough to allow Washington to confront reality.

America’s best hope is that opportunity will come in the final, post–Labor Day stretch of this seemingly interminable presidential campaign. If McCain is elected, the likelihood is that the nation still will be debating Iraq in 2012. If Clinton wins, odds are that the nation will be out sooner than that. Obama holds out the hope for the soonest exit. But calculating how Clinton and Obama would manage Iraq still depends on how each defines “soon.” At the moment, that is as good as the news is going to get. This difficult-to-escape conclusion is even more troubling than the sterility of the Petraeus hearings. The price in blood and money already spent — and yet to be spent — is too high for this sort of obscene Congressional complacency. It is time to stop blaming Bush and start blaming Congress.