President Karzai of Afghanistan has just stolen an election and gotten away with it. Despite being universally criticized as corrupt and incompetent, he is likely to rule Afghanistan for another five years.

And we're expecting American men and women to fight and die to defend his regime? This is nuts, especially if the country descends into civil war and we're expected to take sides. It's time to pull the plug on President Karzai and reconnect with our primary national security objective - defeating Al Qaeda -- not just in Afghanistan but worldwide.

We invaded Afghanistan to defeat Al Qaeda, and we succeeded -- years ago. We defeated Al Qaeda, and toppled their Taliban government hosts in a matter of months. But we then fell victim to mission creep. We stayed to help the Afghanis form a new government; write a constitution; create and train their army and police forces; build their economy; eradicate the poppy crop, and now to fight a growing militancy and a resurgent Taliban. Despite eight years of an ever-expanding mission, we're losing the fight in Afghanistan. According to our top commander in Afghanistan, the much respected Gen. McChrystal, we're facing certain defeat if we don't change strategies and increase our troop strength.

The American military is the most extraordinary and formidable fighting force the world has ever seen. They pulled off a miracle in Iraq and, if given adequate time and resources, they could probably do the same in Afghanistan. The question is not whether they can do it; it's whether they should do it. Does it make sense to focus on Afghanistan as our number one national security priority, especially since Al Qaeda left years ago? Does it make good strategic sense to commit the majority of our military resources to Afghanistan, leaving us vulnerable elsewhere around the world? Is it possible to make a separate peace with Afghanistan' provincial governors, tribal leaders and warlords instead of fighting against them to prop up a corrupt president?

When we cleared Al Qaeda out of Afghanistan in late 2001, they decamped across the border into Pakistan -- a much richer prize from their perspective because it possesses nuclear weapons. They've since allied with the Pakistan Taliban and set their sights on Pakistan's nuclear weapons. Could Al Qaeda return to Afghanistan if the country once again descends into chaos? Sure, but they're much more likely to move on Islamabad than on Kabul.

Yet, as much as Afghanistan's President Karzai has been a disappointment to American interests, Pakistan's President Zardari has been an unexpected surprise. Previous Pakistani leaders paid lip service to defeating Islamic militants within their country. They played us like a fiddle: pledging their support, taking our aid, and sitting on their hands.

President Asif Ali Zardari has proved to be a leader willing leader willing to take the fight to the Taliban and its Al Qaeda allies. Zardari has transferred crack Army troops from the Indian border to the Afghan border. He's cleared the Taliban out of the Swat Valley. He's fighting a serious battle in South Waziristan and has plans to move into North Waziristan. Unlike his predecessor Musharaff, Zardari has come to realize that it's either him or them, especially after Taliban extremists murdered his wife Benazir Bhutto.

Rather than prop up a corrupt and incompetent President Karzai in a country where Al Qaeda is no more, we should instead give President Zardari all the assistance he needs so that his forces can defeat the Taliban and Al Qaeda. He has many flaws, but at least he's willing to fight. He doesn't want our troops, but he needs our military assistance and economic aid. That's where we should be putting our efforts, and redoubling them to prevent Pakistan from falling to Islamic extremists in league with Al Qaeda. As for Afghanistan, we should bypass Karzai and work directly with Afghanistan's individual provincial governors and tribal leaders to keep their regions Al Qaeda-free zones. Let them protect themselves, with generous contributions from us, but without American troops.  It is cheaper to buy friends than kill enemies.

In the end, the greatest threat to America doesn't come from the desolate hills and caves of Afghanistan, but from nuclear weapons in Pakistan. In an ideal world, perhaps America should push for both. But in a world of realities -- where we must set priorities and pick our fights -- an unstable, Taliban-dominated Pakistan with nuclear weapons is far more dangerous to America's security than an unstable Afghanistan.

Kathleen Troia "KT" McFarland served in national security posts in the Nixon, Ford and Reagan Administrations, where she was a Deputy Assistant Secretary of Defense. She does a weekly video-blog for FOX News, DEFCON 3 by KT. Her Web site is KTMcFarland.com.