The request was an unusual one, and President Obama himself made the confidential phone call to Jalal Talabani, the Iraqi president.

Marshaling his best skills at persuasion, Obama asked Talabani, a consummate political survivor, to give up his post. It was Nov. 4, 2010, and the plan was for Ayad Allawi to take Talabani's place. With Allawi, a secular Shiite and the leader of a bloc with broad Sunni support, the Obama administration calculated, Iraq would have a more inclusive government and would check the worrisome drift toward authoritarianism under Prime Minister Nouri al-Maliki.

But Obama did not make the sale. "They were afraid what would happen if the different groups of Iraq did not reach an agreement," recalled Talabani, who turned down the request.

Short of its goals

Obama has pointed to the U.S. troop withdrawal last year as proof that he has fulfilled his promise to end the Iraq war. Winding down a war, however, entails far more than extracting troops. In the case of Iraq, the U.S. goal has been to leave a stable and representative government, avoid a power vacuum that neighboring states and terrorists could exploit and maintain sufficient influence so that Iraq would be a partner or, at a minimum, not an opponent.

But the Obama administration has fallen short of some of those objectives. The attempt by Obama and his senior aides to fashion an extraordinary power-sharing arrangement between Al-Maliki and Allawi never materialized. Neither did an agreement that would have kept a small U.S. force in Iraq to train the Iraqi military and patrol the country's skies. A plan to use U.S. civilians to train the Iraqi police has been cut back. The result is an Iraq that is less stable domestically and less reliable internationally than the United States had envisioned.

A complex situation

White House officials portray their strategy as a success, asserting that the number of civilian fatalities in Iraq is low compared with 2006, when the war was at its height. Politics, not violence, has become the principal means for Iraqis to resolve their differences, they say.

"Recent news coverage of Iraq would suggest that as our troops departed, American influence went with them and our administration shifted its focus away from Iraq," Antony Blinken, the national security adviser to Vice President Joe Biden, said in March. "The fact is, our engagements have increased."

To many Iraqis, the United States' influence is greatly diminished. "American policy is very weak," said Fuad Hussein, chief of staff to Massoud Barzani, president of the semiautonomous Kurdish region. "It is not clear to us how they have defined their interests in Iraq."

The situation the Obama administration inherited was complex. Many Iraqi politicians were worried that Al-Maliki, a Shiite, was amassing too much power and overstepping the Iraqi Constitution by bypassing the formal military chain of command and seeding intelligence agencies with loyalists. Those concerns were aggravated by the political gridlock that plagued Baghdad after the March 2010 elections.

Obama decided to accept Al-Maliki as prime minister while pursuing a deal that would bring Allawi and other members of his Iraqiya bloc into the fold. But engineering a power-sharing arrangement was not easy.

The Americans had a fallback position: A new council on policy would be established, with Allawi in charge. But Al-Maliki and Allawi wrangled over what powers the council would have and it was never formed.

Some members of Allawi's party secured prominent government posts. But the most important feature the White House had pressed for in a power-sharing arrangement existed only on paper.

And without U.S. forces to train and assist Iraqi commandos, the insurgent group Al-Qaida in Iraq is still active in Iraq and is increasingly involved in Syria. With no U.S. aircraft to patrol Iraqi airspace, Iraq has become a corridor for Iranian flights of military supplies to Bashar Assad's government in Syria, U.S. officials say.

Ryan Crocker, the former ambassador to Iraq and Afghanistan, offered his perspective on the tortured negotiations in the country where U.S. troops fought for more than eight years. "I don't think either government handled it as well as it could have been handled," he said. "The U.S. side came to it late." On the Iraqi side, they should have said, 'If you want this don't try to determine our procedures.'"