Give President Barack Obama credit for steadiness. Since ordering a military surge in Afghanistan 18 months ago, he has said consistently he would begin withdrawing some 30,000 troops in July, and pull all U.S combat troops out by 2014. He didn't waver from that timetable Wednesday, a welcome reaffirmation that the end of the long war is in sight.

Still, it's regrettable it will take so long to get there.

The demands of unwinding a 10-year military operation, while preserving the gains made against al-Qaida and the Taliban, may make a three-year, phased withdrawal the best we can do responsibly. But as those years go by, Obama, or his successor, should be on the lookout for any opportunity to pick up the pace.

Most of our objectives in going to war in Afghanistan have been achieved. Osama bin Laden is dead. So are more than half of al-Qaida's leaders, leaving the terrorist organization responsible for the attacks of 9/11 in disarray. Afghanistan has a democratically elected government that, though corrupt, is legitimate. The Taliban has largely been dislodged from its previous strongholds in the country. And the United States and its allies have trained about 300,000 Afghan soldiers and police.

The Afghans must now take responsibility for their own security and, hitting the most political note in his Wednesday speech, Obama said "it is time to focus on nation-building here at home." With the U.S. economy stumbling and the federal government burdened by deficits and debt, there are plenty of other uses for the $120 billion a year the United States is spending in Afghanistan. So this would seem an opportune moment to declare victory and leave. Doing so would certainly be satisfying for a war-weary nation.

Unfortunately pulling out too abruptly could destabilize the region politically and economically, and open the door for Afghanistan to become a haven for terrorists once again. Maintaining a significant combat force in that country for a few more years will enable the U.S. military to keep the pressure on al-Qaida terrorists who have crossed the border and taken refuge in Pakistan. As a practical matter, it will take time to unwind the massive, 10-year military operation in an orderly fashion. And time, together with the prod of a date certain for U.S. withdrawal, may be just what the Afghans need to finally step up to secure their country.

Here at home, Obama's withdrawal timeline -- 10,000 troops out by the end of the year, 23,000 more by next summer and 42,000 more by 2014, leaving a residual force of about 25,000 noncombat troops -- may be the quickest pace that can win broad political acceptance. There is passionate, bipartisan opposition to withdrawing faster and passionate, bipartisan opposition to staying longer.

Despite the wrangling over the pace and politics of withdrawal, the fact is that a long, hard decade after 9/11, the U.S. combat mission in Iraq is finished and U.S. troops are now on a glide path home from Afghanistan. As Obama said, "the tide of war is receding."