The assertion by Secretary of Defense Robert Gates that the United States is prepared to keep troops in Iraq after this year raises troubling questions.

In 2008, President George W. Bush and Iraqi Prime Minister Nouri al-Maliki agreed that all U.S. troops — which now number 47,000 — would leave Iraq by the end of 2011. That agreement attracted substantial political support in both countries. During his 2008 campaign, President Obama promised to end the war, which has lasted eight years, caused more than 4,000 U.S. deaths, and cost this country $900 billion.

Mr. Maliki, in a desperate attempt to gain a second term as prime minister, made a deal for political support with Shiite political and spiritual leader Moktada al-Sadr that included assurances that U.S. forces would leave Iraq by Dec. 31. But Secretary Gates — and President Obama — apparently are under pressure from the U.S. military not to withdraw by the agreed date.

Military leaders want to keep Iraq a four-star-level command. Some also see opportunities for more U.S. arms sales to Iraq. Such sales generate lucrative contracts, including training and other employment opportunities.

Mr. Maliki is nervous about the prospect that Iraqi troops and Kurdish forces may clash when U.S. forces are no longer there to stand between them. Because U.S. troops created the conditions under which his Shiite-dominated government came to power over Iraq’s traditionally ruling Sunnis, his group could lose sectarian battles after a U.S. withdrawal.

Whatever the outcome in Iraq, it is time for America to end its role in this misbegotten and expensive war. The Dec. 31 withdrawal deadline must be met.

First Published April 13, 2011, 4:00 a.m.