Afghanistan's president, Mr. Hamid Karzai, has announced that he wants a formal long-term strategic relationship with the United States. That seems only natural: The U.S. led the invasion of Afghanistan that put Mr. Karzai in power. Others worry that such a relationship could result in a permanent U.S. presence in the country, which could prove unsettling to other nations in the region. Worse, they fear that such a U.S. presence might provoke instability. Given Afghanistan's history, a vacuum is the bigger danger.

Afghanistan has long been an arena of international competition. Over a century ago, Britain and Russia played "the Great Game" across its snowy heights as the two countries fought over access to India. Two decades ago, the Soviet Union tried to impose its own government on Afghanistan's restive warlords, setting off another superpower struggle as the U.S. and its allies -- Saudi Arabia and Pakistan, prime among them -- backed insurgents against the communist regime.

The Soviets lost that war, but no one truly won. Afghanistan descended into chaos as warlords fought for control of the country. Pakistan, Iran and Saudi Arabia backed various groups as they struggled for influence in a nation they each saw as key to their future. The Pakistan-backed Taliban prevailed, but the Islamic government of Mullah Omar antagonized the world with its extremist views and then threw its lot in with Osama bin Laden. Kabul's refusal to hand over bin Laden after the terror attacks of Sept. 11, 2001, prompted a U.S.-led international invasion. The Taliban were routed, and Mr. Karzai took power after historic elections late last year.