Washington needed a coup to shore up political support. Boosting revolutionary ardor kept the Revolution alive. In contrast, Czar Nicholas and Russia's ill-fated Romanov dynasty stand testament to the military consequences of political mismanagement.

So does the one-term presidency of Lyndon Baines Johnson. Lacking a politically viable way to extricate the U.S., and his personal political fortunes, from Vietnam, Johnson instead pursued a doomed strategy of insufficient resources to achieve victory. While politically expedient in a tactical sense, Johnson's conduct of the war ultimately doomed both the war and his own presidency. Last November, with the Johnson presidency in mind, I penned "An Exit Strategy to Die For." In that column, I argued that we are better off bringing our troops home now than to ask them to risk their lives fighting for time until July 2011 rolls around and a politically expedient withdrawal commences.

Over the last year, events have persuaded me that this view remains correct. The coalition of the willing is winnowing as allies, convinced of the inevitably of a U.S. pullout, race us for the exits.

American casualties are now higher than in 2001. The chronically unstable Karzai government faces a fresh financial crisis, beseeching bailout-fatigued U.S. taxpayers to keep the Bank of Kabul solvent. Meanwhile the Taliban, burrowed into the towns and villages and biding their time in mountain fastnesses, patiently await the expiry date of Obama's necessary war.

Into this grim scenario, Petraeus has now made a play for Obama to reconsider the deadline. In a recent television interview, he said it is his duty to give the commander in chief his "best professional military advice" about whether July is too soon to remove troops. Separately, other policymakers have begun suggesting the July withdrawal may not be firm, injecting a hint of ambiguity into official statements. But in last week's Oval Office address, the president reconfirmed, precisely, that the withdrawal shall begin in July, as he ordered in his West Point policy announcement speech last year.

In the retirement speech of one of our greatest fighting generals, Gen. McChrystal -- whose self-inflicted career immolation still remains unexplained, but undoubtedly patriotically motivated -- we may have been given a first hint of his motivation when he observed: "Caution and cynicism are safe, but soldiers don't want to follow cautious cynics.

They follow leaders who believe enough to risk failure or disappointment for a worthy cause."

I repeat what I wrote last November: Bring the troops home. We'll need them later, God knows.