Why U.S. needs to stay in Afghanistan - Peter Bergen, CNN National Security Analyst

(CNN) - President Barack Obama says that the last American troops will leave Afghanistan at the end of 2016. This happens to roughly coincide with the end of his second term in office and also fulfills his campaign promise to wind down America's post-9/11 wars.

But is it a wise policy?  Short answer: Of course not.

One only has to look at the debacle that has unfolded in Iraq after the withdrawal of US troops at the end of 2011 to have a sneak preview of what could take place in an Afghanistan without some kind of residual American presence. Without U.S. forces in the country, there is a strong possibility Afghanistan could host a reinvigorated Taliban allied to a reinvigorated al Qaeda.

Needless to say, this would be a disaster for Afghanistan. But it would also be quite damaging to U.S. interests to have some kind of resurgent al Qaeda in the country where the group trained the hijackers for the 9/11 attacks.

It would also be disastrous for the Democratic Party, should it win the presidency in 2016, to be the party that "lost" Afghanistan. After all, the Democratic Party is viewed by some as weaker on national security than the Republicans and it is inevitable that without some kind of residual American presence in Afghanistan al Qaeda would gain sufficient strength to launch an attack from the Afghan-Pakistan border region against American interests.

An easy way for potential Democratic Party presidential candidates such as Hillary Clinton to distinguish their national security policies from Obama's would be to say that they are in favor of some kind of long-term U.S. military presence in Afghanistan and to argue that it would be needed to avoid an Iraq-style outcome there.

Similarly, as the Republican Party starts ramping up for the 2016 campaign, potential candidates such as Jeb Bush can distinguish themselves from the isolationist Rand Paul wing of the party by saying that they are committed to a long-term presence in Afghanistan.

This U.S. military presence in Afghanistan doesn't have to be a large, nor does it need to play a combat role, but U.S. troops should remain in Afghanistan to advise the Afghan army and provide intelligence support.  Keeping a relatively small, predominantly U.S. Special Forces, presence in Afghanistan to continue to train the Afghan army past December 2016 is a wise policy that would benefit both Afghans and Americans.

Both the Democratic and Republican parties should adopt such a plan in their platforms as they gear up for the 2016 campaign.   Read More at CNN