Among Dana Carvey's most brilliant sketches on Saturday Night Live were his dead-perfect impersonations of President George H. W. Bush, which made a permanent contribution to America's political language. "Not gonna do it!" Carvey-as-Bush would say. "Wouldn't be prudent!"

What Carvey grasped is that Bush 41 was a conservative not so much by ideology as by temperament. Prudence really was one of his cardinal virtues.

Prudence went on vacation during the administration of the second President Bush, but it's back as the hallmark of President Barack Obama's approach to foreign policy. And it was the underlying theme of Obama's speech on Afghanistan last week.

You would think this would be popular. But it turns out that Obama finds himself almost alone in his effort to define a broad new middle ground in international affairs. It's not that the center isn't holding. It's that most politicians don't seem to want to go near it.

Here is the most important passage of Obama's address: "We must chart a more centered course. Like generations before, we must embrace America's singular role in the course of human events. But we must be as pragmatic as we are passionate; as strategic as we are resolute. When threatened, we must respond with force—but when that force can be targeted, we need not deploy large armies overseas."

Obama is trying to get out of Afghanistan, carefully. He's trying to put "a difficult decade" of war behind us. If he is re-elected, he would chart a new course freed from the two enormous military engagements that George W. Bush undertook.

The problem for Obama is that what he sees as a grand revival of bipartisanship in foreign policy is being dismissed widely as an improvised set of split-the-difference tactical choices.

His withdrawal schedule from Afghanistan is too slow for the doves, too quick for the hawks. In the case of Libya, he's too aggressive for those weary of American military intervention and not bold enough for those who think the United States has a moral obligation to bring down the Gaddafi dictatorship. The fact that almost all our troops will be out of Iraq by the end of the year goes unheralded.

Politically, says Rep. Jim McGovern (D-Mass.), a longtime advocate of a withdrawal from Afghanistan, Obama risks being in the position of Democrats in 1968. Lyndon Johnson and Hubert Humphrey were held accountable for the Vietnam War while Republican Richard Nixon could seek votes by promising to end it without offering any details as to how.

With so many Republicans moving off to the dovish side, Obama could find himself caught in a weird pincer movement between these newly antiwar Republicans and those who will say that he squandered a chance to "win" in Afghanistan by not giving the generals time to use our surge troops during one more "fighting season."

The administration is stuck making a case whose only virtue is that it might turn out to be right. The United States has done what it could to improve the situation on the ground in Afghanistan. We have to decide whether this commitment will end, or whether there will be an endless series of "fighting seasons" in which we need to give it one more try. A political settlement is the only way out, and it's not obvious that one more round of fighting would substantially improve the outcome of those discussions.

It's easy, for me at least, to identify with those who want to move out faster. But Obama is not being excessively prudent to worry that a quicker withdrawal could disrupt our alliances, undo our achievements on the ground, and weaken our efforts to leave a relatively stable situation behind when we do get out. Yes, wars are harder to end than to start, especially when no clean and clear victory is possible. Other people's civil wars are like that.

There are times when Obama's obsession with finding some sensible middle ground is deeply frustrating. In the budget talks, he has made a variety of concessions to Republicans only to have them walk out and insist on defining bipartisanship as getting whatever it is they want. Obama's conflict avoidance has led him to default on making a case for his own domestic policies.

But his effort to find a more stable middle ground in foreign policy deserves more support than it's getting. There are worse things than to deserve comparisons with George H. W. Bush, Dana Carvey's brilliant barbs notwithstanding. 

(c) 2011, Washington Post Writers Group

Related: Stuck, by Margaret O'Brien Steinfels
Absurd, or Worse by David Kaiser
The War We Can't Win, by Andrew Bacevich