It will not be too difficult to accomplish the first two objectives, just as counterinsurgency made progress in Iraq under Bush's surge strategy. But it is far from certain that the third objective can be reached within the timeframe Obama has set.

Karzai is ready to cooperate and is dependent on America to help train his security forces, but the difficulties are huge, because Afghanistan is not a modern nation but a tribal country. Karzai controls only 20 percent of its territory. In remote mountain areas, tribes hide the Taliban and villagers sympathize with them. The U.S. and its allies can quell the insurgency, but cannot destroy the organizations or ideas of the Taliban. As in Iraq, America is not looked as a liberator but as an invader and an occupier and poorly-educated see it as reasonable and legitimate for them to attack American soldiers. Karzai's fading popularity was demonstrated in the recent presidential election. The American government can make its support and assistance conditional on Karzai meeting benchmarks regarding the recruitment and training of security forces, improvements in governance, and battling corruption, and so on, but it is inconceivable that Karzai will be able to meet their targets.

Afghanistan looks more and more like becoming a nightmare for Obama. Historically, it has been the graveyard of empires. It buried the British Empire in the 19th century and the Soviet Union in the 20th century. Not much has changed over the past two centuries. Foreigners can win easy military victories in the short term, but their armies are swallowed up in the long term.

America is unlikely to be an exception. The Afghanistan War has already lasted more than 8 years and is, by some measures, the longest war in American history. Many compare it with the Vietnam War. Lyndon B. Johnson was an ambitious president who promised to build "the Great Society", and indeed he had many legislative successes domestically. But he was abandoned by his party and the public after he escalated the Vietnam War. His legacy and reputation were defined by Vietnam.

Obama was sworn in the White House bearing a dream of "change" and "hope" for Americans confronted with economic recession and two messy foreign wars. He had blueprints for domestic change, on the economy, new energy sources, reforming health care, regulating the financial markets and so on. But Democratic Party leaders and congressmen have started to worry that he is losing his focus and will be dragged down by the Afghan war. His former ardent supporter Nancy Pelosi said of his surge strategy, "That may be one option, but I don't think that has a good prospect."

Obama understands both the strategic dangers as well as the political risks of his policy. But he narrowed the options himself when he committed to shifting the center of counter-terrorism from Iraq to Afghanistan and Pakistan. The Afghanistan War is no longer Bush's war; it is Obama's war. And it is likely to turn into a nightmare for him whatever he chooses to do. That is a great tragedy.