If your heart is weary of its disappointment in Barack Obama–over the scuttled public option in health care, his Bush-friendly Justice Department, or his decision to send 30,000 new troops and more than $30 billion into Afghanistan–give it a little defibrillation with this thought: What if Obama catches Osama bin Laden in the next 18 months?

Big if, I know. And Obama didn’t say that’s what all those boots on the ground (plus all those shoes worn by the tens of thousands of contractors who will accompany them) were about; in fact, the president mentioned Osama just once in his Afghanistan speech at West Point, and then only in passing, when he said the Taliban’s refusal to give bin Laden up justified our first invasion.

But after watching a Republican Congress with razor-thin majorities get everything it wanted for 10 years or so, and then watching a Democratic Congress with razor-thin majorities get little more the blame for a bank bailout engineered by the Bushies, harpooning the Great White Whale for American vengeance is just about the only card Obama can pull out of his hat to restore faith in his leadership.

And boy, would it ever. Catching the beanpole bomber of jihad would not just be about showing George W. Bush up for the abject failure that he was; after all, we can’t even be sure that getting bin Laden was ever really Bush’s goal. Rep. Maurice Hinchey (D-NY) said on MSNBC last week that the Bush administration "apparently intentionally let bin Laden get away" when we had him cornered in Tora Bora in 2002 because they knew if they nabbed him "there would be no justification for an invasion in Iraq."

We do have some reason to think that, while still demanding more blood and treasure for these wars, the Obama administration may well have gone back to first principles on the whole conflict. Earlier this week, Gen. Stanley McChrystal told Congress, "It would not defeat al-Qaida to have him captured or killed, but I don’t think that we can finally defeat al-Qaida until he is captured or killed."

Not as ornery as Bush’s "dead or alive," but a bit more believable. Plus, we have this, from CBS correspondent Lara Logan, on Colbert last night:

Most folks would agree that you’re more likely to catch someone if you actually look for him. Getting bin Laden, even at this late date, would accomplish the first and last thing that many Americans want out of these irresolvable wars, a sense of payback for the Twin Towers, the Pentagon, and the passengers on those three planes. True, capturing or killing Osama might make him a martyr, but it would restore some lost faith in America’s ability to do what it says it means to do, and it would have one very real and salutary effect: It would give Obama everything he needs to say we’ve won the war and can now go home.

At a stroke Obama would win his mojo back, and the Dems would likely find what they’re trying to achieve domestically somewhat easier. The GOP would be confounded. How could anyone accuse Obama of being a socialist Muslim traitor if he were the man who brought in Osama? Would anyone take Republican claims to being the "national security" party seriously ever again? And some of us on the left would grudgingly have to admit that the $30 billion had not been entirely misspent–as long as Obama used OBL’s capture as the excuse to really leave Afghanistan. (I know, an even bigger if.)

One reason Vietnam has been such a blight on our culture for 40 years is that the Boomer generation decided simply to leave the domestic politics surrounding that war unresolved. There were no consequences for the political class for how it started, pursued, or ended that war; we just pulled out and agreed to disagree. Progressives decided to be satisfied with nailing Richard Nixon for saying four-letter words on the White House tapes, and conservatives agreed to stoke a frustrated rage with fantasies of MIAs and government conspiracies. How could we learn the lessons of Vietnam if we never came to terms publicly with what they were?

Clearly the Bush 43 wars are similar mistakes–the strategery on which their launch was based was irredeemably flawed, and getting out is the only solution. But for any president to openly admit defeat in either one would be tantamount to political suicide (something LBJ learned well), and anyway these quagmires were intentionally left behind like mines, waiting for a Democrat to step on them. So–given the American public’s reluctance to directly assess the limits on our vaunted military power–we need a marketing strategy that would allow us to crank up the noise machine for rah-rahs and cover our impecunious skedaddle.

Remember the media whoop when Saddam was captured? Bin Laden’s capture would be entirely more satisfying to most of the country, and certainly more meaningful back home than securing a highway or building girls’ schools. Americans don’t like White Whales, but we have a sort of grudging respect for those willing to destroy themselves by chasing after pale cetaceans. The right meant such self-destruction to be Obama’s only choice.

So, Mr. President, break the cycle–nab the ringleader and get outta town.

Besides, it’s the only sensible way to make war with a Nobel Peace Prize in your hand.