As President Obama decides whether to sign off on Gen. Stanley McChrystal's request for a massive troop hike in Afghanistan - the president is slated to conduct high-level meetings today and tomorrow - his usual critics are already complaining that his pause for reflection is proof that he's a wimp and a wuss. As they see it, Obama should speedily say yes because the military commander in the field always knows best. For instance, from the cheap seats, here's potential 2012 challenger Mitt Romney: "This is not the time for Hamlet in the White House."

But presidents are not supposed to rubber stamp the military brass; that's not how our system is supposed to work. The head of the military is a civilian - that would be Obama - and the civilian, looking at the big picture, is constitutionally empowered to have the last word. The Pentagon has been trying to box Obama in, by leaking McChrystal's 40,000 troop hike request to The Washington Post last week - with McChrystal advertising himself in a 60 Minutes segment the other night - but it doesn't necessarily follow that Obama should forfeit his responsibility to think for awhile outside the box.

And those who support Obama on this point can hardly be typecast as liberals. To cite one example, Michael O'Hanlon, a Washington think-tanker best known for his outspoken hawkishness on Iraq, told an audience of neoconservatives the other day that they should cut the president some slack. In his words: "Mr. Obama is entitled to think twice about (McChrystal's recommendation). He is entitled to wonder, just how precise is this military arithmetic? Just how promising is this counter-insurgency strategy anyway? I do think generals should say what they think they need. But presidents should also digest that request."

O'Hanlon said that everybody should indulge Obama "at least for a few weeks of deliberation and indecision. If he is still in November where he is today, I will not be defending him. But I think where he is at this moment is understandable."

Nor is it even clear that the military establishment is unanimously enthused about the prospect of pouring 40,000 more soldiers into Afghanistan. Reports indicate that Gen. George Casey Jr., the Army chief of staff, is very concerned that such a commitment would further stress the forces that have been overly stressed for years on two fighting fronts. Colin Powell, the retired military leader, has also reportedly told Obama that he too is skeptical about the eficacy of hiking the troop levels; in remarks to reporters last week, Powell also said, "You have to not just add troops. You need a clear definition of your mission and then you can determine whether you need more troops or other resources."

Maybe Obama will ultimately make the right decision, maybe not. The question is, what's the best way to fight what he has called a "war of necessity?" And the point is, he's the one to make the decision, doing so after a careful weighing of all relevent factors. The military commanders are not supposed to dictate policy, nor is it smart to assume that they have a monopoly on wisdom. In fact, history has already demonstrated that they don't.

Best example: The 1962 Cuban missile crisis.

Anyone needing a primer on the importance of civilian checks and balances should read One Minute to Midnight, the best (and newest) book on the confrontation that nearly incinerated the world. As author Michael Dobbs recounts (drawing on unparalleled access to previously confidential documents), the military unanimously urged that President Kennedy respond to the presence of nearby Soviet WMDs by OKing their recommendation for "surgical" air attacks followed by a massive American invasion of Cuba. But Kennedy, fearing that such a move would escalate to nuclear war, steadfastly refused - thus prompting one top military leader to complain that the president's refusal was "almost as bad as the appeasement at Munich." And as Kennedy kept deliberating day after day, his Republican critics in Congress yelled that he was "weak."

The military advisors were convinced that America could win a nuclear war, and said so in the meetings. Kennedy was not bedazzled by the advice. He asked the brass how many casualties there would be if just one Soviet missile detonated above American soil. The brass' response: about half a million people. To which Kennedy had the temerity to reply, "That was the number of casualties we had in the Civil War, and it's taken us almost a century to get over that."

Ultimately, of course, Kennedy patiently extricated us from the crisis via carefully calibrated diplomacy (plus some luck). Dobbs, citing much documentation, makes it quite clear that if Kennedy had merely rubber-stamped the military's bellicose advice, the odds are high that none of us would be around today.

Yeah, I know, the Cuban missile crisis is an extreme example, one that is not directly analogous to the decision we face in Afghanistan today. But the principle is the same. Just as Kennedy utilized his knowledge of history to check and balance his military leaders (he was well aware of how military-driven decisions prompted Europe to blunder into World War I), Obama and his civilian team is likely to reference history (if not Cuba, then Vietnam) in order to check and balance those who would deepen our ground involvement without even a wise pause for reflection.