The lesson of Afghanistan

President Barack Obama was plainly bowing to the inevitable last October when he shelved plans to bring home all U.S. troops from Afghanistan by end of this year. It was clear that the war there wasn't going well and that the Afghan Army the U.S. had spent more than 10 years and billions of dollars to train and equip still couldn't be counted on to defend the country against Taliban and al-Qaeda militants. Mindful of the swift collapse suffered by U.S.-trained forces in Iraq in 2011 after the precipitous withdrawal of American forces there, the Obama administration wasn't about to let the same thing happen again in Afghanistan.

But the result of that decision has been to force American policymakers to face up to a prospect they had long sought to avoid: a more or less permanent U.S. military presence in Afghanistan that could stretch out for decades to come. That's exactly the opposite of what Mr. Obama promised on the campaign trail in 2008 when he vowed to end America's longest war, yet it's what the general he nominated to lead the conflict predicts. At a Senate confirmation hearing today , Lt. Gen. John Nicholson said he foresaw the possibility of an indefinite American commitment to Afghanistan like we have in Germany and South Korea. The reality on the ground is that there's no light at the end of this tunnel.

Granted, there's plenty of blame to go around for the U.S. military's inability to extricate itself from Afghanistan, and not all of it falls on Mr. Obama's watch. Former President George W. Bush bears a share of responsibility for his decision to topple the Taliban in 2001, after the terrorist attacks on New York and Washington, then take his eye off the ball two years later when the U.S. invaded Iraq. That gave Afghan insurgents time to recover and regroup. Likewise, Mr. Obama reluctantly accepted the 2009 "surge" of 33,000 troops to Afghanistan to counter the resurgent Taliban, but then he withdrew them before the mission was accomplished in order to have them home by Election Day in 2012.

In hindsight it's easy to see how both decisions ended up deepening the quagmire Afghanistan has become. But the next president is going to inherit a situation in which he or she can either choose to repeat the mistakes of the past or make a clean break with them by recognizing that there's no quick or easy path to victory in Afghanistan and that stabilizing the situation there enough to prevent terrorist groups from using it as a base for attacks on the U.S. and its allies may be the closest thing to success we can achieve. Even that could require a generational struggle in which our conventional military forces are at a long-term disadvantage against the hit-and-run tactics of lightly armed guerrillas hiding among the civilian population.

Our involvement in Afghanistan should serve as a cautionary tale about the perils of military adventurism, just as the Iraq War did, but it's striking how differently those lessons have been absorbed by the presidential contenders in the two parties. On the Democratic side, we're witnessing a debate between Sen. Bernie Sanders and Hillary Clinton about whether her vote to authorize the Iraq War represents a fatal lack of good judgment. But on the Republican side, with the exception of the isolationist Sen. Rand Paul, we're witnessing a contest to see who can be the most bellicose when it comes to new threats like ISIS and the civil war in Syria. Sen. Ted Cruz's loose talk of "carpet bombing" terrorists and making the sand "glow in the dark" is just political bluster that, if actually carried out, would virtually guarantee a U.S. defeat by turning the whole Muslim world against us.

The only way to win the war in Afghanistan is to recruit and train local forces committed to defending their country and supporting them over the long-term with U.S. airpower, logistics and intelligence capabilities, and it's the only way forward against ISIS as well. That's what the U.S. is really good at, but it will require strategic patience and a commitment to seeing the conflict through to the end no matter how long the fighting continues. The conflicts ranging from Syria to Afghanistan won't be won under the next president nor perhaps for several more to come, regardless of which party occupies the White House. The next commander-in-chief may not like hearing that, but it's something he or she is going to have to learn to live with because the alternatives are even worse.