BAGHDAD, July 23 — While Washington is mired in political debate over the future of Iraq, the American command here has prepared a detailed plan that foresees a significant American role for the next two years.

The classified plan, which represents the coordinated strategy of the top American commander and the American ambassador, calls for restoring security in local areas, including Baghdad, by the summer of 2008. “Sustainable security” is to be established on a nationwide basis by the summer of 2009, according to American officials familiar with the document.

The detailed document, known as the Joint Campaign Plan, is an elaboration of the new strategy President Bush signaled in January when he decided to send five additional American combat brigades and other units to Iraq. That signaled a shift from the previous strategy, which emphasized transferring to Iraqis the responsibility for safeguarding their security.

That new approach put a premium on protecting the Iraqi population in Baghdad, on the theory that improved security would provide Iraqi political leaders with the breathing space they needed to try political reconciliation.

The latest plan, which covers a two-year period, does not explicitly address troop levels or withdrawal schedules. It anticipates a decline in American forces as the “surge” in troops runs its course later this year or in early 2008. But it nonetheless assumes continued American involvement to train soldiers, act as partners with Iraqi forces and fight terrorist groups in Iraq, American officials said.

The goals in the document appear ambitious, given the immensity of the challenge of dealing with die-hard Sunni insurgents, renegade Shiite militias, Iraqi leaders who have made only fitful progress toward political reconciliation, as well as Iranian and Syrian neighbors who have not hesitated to interfere in Iraq’s affairs. And the White House’s interim assessment of progress, issued n July 12, is mixed.

But at a time when critics at home are defining patience in terms of weeks, the strategy may run into the expectations of many lawmakers for an early end to the American mission here.

The plan, developed by Gen. David H. Petraeus, the senior American commander, and Ryan C. Crocker, the American ambassador, has been briefed to Defense Secretary Robert M. Gates and Adm. William J. Fallon, the head of the Central Command. It is expected to be formally issued to officials here this week.

The plan envisions two phases. The “near-term” goal is to achieve “localized security” in Baghdad and other areas no later than June 2008. It envisions encouraging political accommodations at the local level, including with former insurgents, while pressing Iraq’s leaders to make headway on their program of national reconciliation.

The “intermediate” goal is to stitch together such local arrangements to establish a broader sense of security on a nationwide basis no later than June 2009.

“The coalition, in partnership with the government of Iraq, employs integrated political, security, economic and diplomatic means, to help the people of Iraq achieve sustainable security by the summer of 2009,” a summary of the campaign plan states.

Military officials here have been careful not to guarantee success, and recognized they may need to revise the plan if some assumptions were not met.

“The idea behind the surge was to bring stability and security to the Iraqi people, primarily in Baghdad because it is the political heart of the country, and by so doing give the Iraqis the time and space needed to come to grips with the tough issues they face and enable reconciliation to take place,” said Col. Peter Mansoor, the executive officer to General Petraeus.

“If eventually the Iraqi government and the various sects and groups do not come to some sort of agreement on how to share power, on how to divide resources and on how to reconcile and stop the violence, then the assumption on which the surge strategy was based is invalid, and we would have to re-look the strategy,” Colonel Mansoor added.

General Petraeus and Ambassador Crocker will provide an assessment in September on trends in Iraq and whether the strategy is viable or needs to be changed.

The previous plan, developed by Gen. George W. Casey Jr., who served as General Petraeus’s predecessor before being appointed as chief of staff of the Army, was aimed at prompting the Iraqis to take more responsibility for security by reducing American forces.

That approach faltered when the Iraqi security forces showed themselves unprepared to carry out their expanded duties, and sectarian killings soared.

In contrast, the new approach reflects the counterinsurgency precept that protection of the population is best way to isolate insurgents, encourage political accommodations and gain intelligence on numerous threats. A core assumption of the plan is that American troops cannot impose a military solution, but that the United States can use force to create the conditions in which political reconciliation is possible.

To develop the plan, General Petraeus and Ambassador Crocker assembled a Joint Strategic Assessment Team, which sought to define the conflict and outline the elements of a new strategy. It included officers like Col. H. R. McMaster, the field commander who carried out the successful “clear, hold and build” operation in Tal Afar and who wrote a critical account of the Joint Chiefs of Staff role during the Vietnam War; Col. John R. Martin, who teaches at the Army War College and was a West Point classmate of General Petraeus; and David Kilcullen, an Australian counterinsurgency expert who has a degree in anthropology.

State Department officials, including Robert Ford, an Arab expert and the American ambassador to Algeria, were also involved. So were a British officer and experts outside government like Stephen D. Biddle, a military expert at the Council on Foreign Relations.

The team determined that Iraq was in a “communal struggle for power,” in the words of one senior officer who participated in the effort. Adding to the problem, the new Iraqi government was struggling to unite its disparate factions and to develop the capability to deliver basic services and provide security.

Extremists were fueling the violence, as were nations like Iran, which they concluded was arming and equipping Shiite militant groups, and Syria, which was allowing suicide bombers to cross into Iraq.

Like the Baker-Hamilton commission, which issued its report last year, the team believed that political, military and economic efforts were needed, including diplomatic discussions with Iran, officials said. There were different views about how aggressive to be in pressing for the removal of overtly sectarian officials, and several officials said that theme was toned down somewhat in the final plan.

The plan itself was written by the Joint Campaign Redesign Team, an allusion to the fact that the plan inherited from General Casey was being reworked. Much of the redesign has already been put into effect, including the decision to move troops out of large bases and to act as partners more fully with the Iraqi security forces.

The overarching goal, an American official said, is to advance political accommodation and avoid undercutting the authority of the Iraqi prime minister, Nuri Kamal al-Maliki. While the plan seeks to achieve stability, several officials said it anticipates that less will be accomplished in terms of national reconciliation by the end of 2009 than did the plan developed by General Casey.

The plan also emphasizes encouraging political accommodation at the local level. The command has established a team to oversee efforts to reach out to former insurgents and tribal leaders. It is dubbed the Force Strategic Engagement Cell, and is overseen by a British general. In the terminology of the plan, the aim is to identify potentially “reconcilable” groups and encourage them to move away from violence.

However, groups like Al Qaeda in Mesopotamia, a Sunni Arab extremist group that American intelligence officials say has foreign leadership, and cells backed by Iran are seen as implacable foes.

“You are not out there trying to defeat your enemies wholesale,” said one military official who is knowledgeable about the plan. “You are out there trying to draw them into a negotiated power-sharing agreement where they decide to quit fighting you. They don’t decide that their conflict is over. The reasons for conflict remain, but they quit trying to address it through violence. In the end, we hope that that alliance of convenience to fight with Al Qaeda becomes a connection to the central government as well.”

The hope is that sufficient progress might be made at the local level to encourage accommodation at the national level, and vice versa. The plan also calls for efforts to encourage the rule of law, such as the establishment of secure zones in Baghdad and other cities to promote criminal trials and process detainee cases.

To help measure progress in tamping down civil strife, Col. William Rapp, a senior aide to General Petraeus, oversaw an effort to develop a standardized measure of sectarian violence. One result was a method that went beyond the attacks noted in American military reports and which incorporated Iraqi data.

“We are going to try a dozen different things,” said one senior officer. “Maybe one of them will flatline. One of them will do this much. One of them will do this much more. After a while, we believe there is chance you will head into success. I am not saying that we are absolutely headed for success.”