I'm nearly finished with Rick Perlstein's Nixonland, and there are many lessons in it that today's Democrats should take to heart. One of the biggest is that attempting to out-hawk Republicans may have occasional electoral payoffs in the short term, but in the long term it brings serious consequences. That's yet another reason why I oppose escalation in Afghanistan - and disagree with Obama on that issue more than any other by far.

As Perlstein convincingly shows, Johnson's landslide 1964 victory and sweeping legislation package thereafter seemed to cement an American consensus. But beginning with the Watts riots in 1965, law-and-order right-wingers like Ronald Reagan benefited more and more from a backlash against the Great Society.

Johnson's second term witnessed severe disruption connected to domestic social issues. However - and perhaps Perlstein would disagree with me here - Vietnam, and the social disruptions Johnson's foreign policy caused, were what finally broke the back of America's consensus. Even with the riots of the 1960s, I think that without Vietnam Johnson would today be considered one of America's greatest presidents. Moreover, I think Democrats would have won in 1968. Until Vietnam tore us apart, a majority of Americans backed Kennedy and Johnson's vision for our country. For that matter, I think a majority still do.

The set of factors that combined to create a Democratic loss in 1968 is shocking. Riots in our cities, a failed war at home, a divided party, the assassination of Robert Kennedy, the debacle of the Chicago convention, and the selection of Hubert Humphrey, a terrible candidate, as the nominee. Yet despite all of those tragedies, Richard Nixon only barely edged out Humphrey, winning by less than one percentage point - and by a plurality at that, given George Wallace's 13.5% share of the vote (which might have been higher, as Perlstein points out, if his running mate had not made remarks favoring the use of nuclear weapons in Vietnam).

A big piece of Nixon's 68 campaign - which really began in 1966, or earlier - was attacking Democrats on Vietnam and exploiting divisions within their ranks surrounding the issue of the war.

So let me simplify: Subtract Vietnam, and we would be looking at a different and better America today. 58,000 young Americans lost their lives, along with countless Vietnamese, and the party that forged the New Deal and the Great Society was left shattered until November 4th, 2008.

When John Kennedy ran against Richard Nixon in 1960, maybe it made sense, electorally, to outhawk the administration on Cold War issues. But pursuing that hawkishness once in office tore the party and the country asunder.

I wouldn't characterize Carter as a hawk on foreign policy, but certainly some of his worst foreign policy moments came when he turned away from progressive values, allowing the despicable Shah into our country after the Iranian Revolution (thus touching off the hostage crisis) and attempting a far-fetched rescue mission.

History has shown that Democrats don't need to be tough on foreign policy to win elections, but they do need to be smart.

Democrats don't always learn their history, of course. From 2002-2004, Democrats again suffered the consequences of trying to prove themselves hawks, this time on Iraq. The 2002 elections swept out many Democrats who thought they could go toe to toe with Republicans on talking tough on Iraq, while Senator Paul Wellstone's courageous stand against the war actually boosted him in the polls. And in 2004, John Kerry paid dearly for his Iraq war vote.

If Democrats can lay out a foreign policy stance that resonates with progressive values and effectively addresses global threats and problems, they can dominate the debate. That stance, in its rough outlines, is that America will respond swiftly and decisively to any attack. But we will not occupy foreign lands for extended periods of time, and we will not preemptively attack other countries.

I've gone through all this history in order to make a comment on the present situation in Afghanistan. I understand why Barack Obama out-hawked John McCain, and even George Bush, on Afghanistan during the general election. But now that he is president-elect - with a historic opportunity to rebuild the country and the party - I pray that he will avoid Kennedy and Johnson's mistakes. I also pray that he will convey a progressive foreign policy stance to the American people in clear and precise terms.

Afghanistan is not Vietnam. We do not have a draft. We do not have massive protest movements against Afghanistan, a war that many Americans have forgotten about. But I am wary of the consequences of allowing conflicts to fester or worse, escalating them.

We need to address domestic problems. Obama was elected on a mandate that favors greater regulation on Wall Street, passage of universal health care, a new direction for energy policy, and closing tax loopholes for corporations. To accomplish these goals, we must clear the decks of dubious foreign entanglements. From a moral, fiscal, and psychological standpoint, we must bring the wars in Iraq and Afghanistan to a responsible close in order to focus our efforts on rebuilding our country while innovative diplomacy restores our alliances and reaches out to new partners around the world.

I therefore urge President-elect Obama to rethink his position on Afghanistan. Those progressives who think in moral terms should recognize the imperative to end the killing of civilians, address Afghanistan's humanitarian crisis, and exit the war in a timely fashion. And to the most cynical and electorally-minded Democrats, I say that digging our heels in with these foreign wars that do not make America safer and threaten to drag out indefinitely is a proven way to fracture our party and earn defeat at the ballot box. I'm not saying that Obama will lose in 2012 if he fails to withdraw from Afghanistan - incumbents, after all, tend to win - but if we are still in Afghanistan in 2014, 2016, or later, eventually Democrats will pay an electoral price. The risks - for the party, the country, and the world - vastly outweigh the potential benefits of sending scores more young men to die in Afghanistan, or to invade Pakistan, a highly unstable nation of 160 million with unsecured nuclear weapons.

Who could have predicted in 1960 the turbulence of 1968? But if we've learned anything from those times, it's that Democrats can weather a lot of domestic storms - but they can't convince Americans that ideological wars against small countries are part of a successful progressive vision. We can win the wars that count; Democrats have before. But the occupation of Afghanistan, where military objectives have long ago become nebulous, is a conflict that demands a sound diplomatic and political policy, not a military escalation. If Democrats are serious about governing, they will get us out of the quagmires that Bush got us into - not deeper in.