Asked if that was his last visit, given how much events on the ground have changed since then, he jumped in before the question was finished, saying, “Given how important this is, why haven’t I gone back?”
In an hourlong interview on Wednesday, Mr. Obama made clear that forging a new relationship with Iran would be a major element of a broad effort to stabilize Iraq as he executed a speedy timetable for the withdrawal of American combat troops.
Mr. Obama said that Iran had been “acting irresponsibly” by supporting Shiite militant groups in Iraq. He also emphasized that Iran’s suspected nuclear weapons program and its support for “terrorist activities” were serious concerns.
But he asserted that Iran’s support for militant groups in Iraq reflected its anxiety over the Bush administration’s policies in the region, including talk of a possible American military strike on Iranian nuclear installations.
Making clear that he planned to talk to Iran without preconditions, Mr. Obama emphasized further that “changes in behavior” by Iran could possibly be rewarded with membership in the World Trade Organization, other economic benefits and security guarantees.
“We are willing to talk about certain assurances in the context of them showing some good faith,” he said in the interview at his campaign headquarters here. “I think it is important for us to send a signal that we are not hellbent on regime change, just for the sake of regime change, but expect changes in behavior. And there are both carrots and there are sticks available to them for those changes in behavior.”
In his Democratic presidential bid, Mr. Obama has vigorously sought to distinguish himself on foreign policy from his rivals, particularly Senator Hillary Rodham Clinton of New York, by asserting that he would sit down for diplomatic meetings with countries like Iran, North Korea and Syria with no preconditions.
The suggestion, which emerged as a flash point in the campaign, has prompted Mrs. Clinton to question whether such an approach would amount to little more than a propaganda victory for the United States’ adversaries and to question the experience of Mr. Obama, a first-term senator from Illinois. Other Democrats, in turn, have criticized Mrs. Clinton for an approach to Iran they call too hawkish, including a vote for a nonbinding resolution describing the Islamic Revolutionary Guard Corps in Iran as a terrorist organization.
Mr. Obama’s willingness to conduct talks at the highest level with Iran also differs significantly from the Bush administration’s approach.
The administration has authorized Ambassador Ryan C. Crocker to discuss Iraq with Iranian officials. But the White House has also said it will not engage in high-level talks on other issues unless Iran first suspends its program to enrich uranium. Nor has the Bush administration advertised in detail the possible rewards for a change of Iranian behavior.
Through most of the interview, Mr. Obama spoke without referring to notes. At one point near the end of the session, he leaned forward in his chair and looked at a yellow legal pad on the table in front of him, which listed points where he believed he and Mrs. Clinton differ on how to go forward in Iraq.
“You don’t want to look backwards, but obviously our general view about this mission as a whole has been very different,” Mr. Obama said. “She missed the strategic interests that should have dictated whether we went to Iraq in the first place or not.”
Mrs. Clinton has said that after carrying out major troop withdrawals she would leave a residual force in Iraq to fight Al Qaeda in Mesopotamia, battle other terrorist groups, train the Iraqi Army and deter Iranian intervention.
Mr. Obama has also talked about keeping a limited force in Iraq after withdrawing American combat units at the rate of one or two per month. But he insisted in the interview that the mission of his residual force would be more limited than that posited by Mrs. Clinton.
Mr. Obama said, for example, that the part of the residual force assigned to counterterrorism might be based outside Iraq. He also emphasized that the residual force would not have the mission of deterring Iranian involvement in Iraq.
He said he would commit to training Iraqi security forces only if the Iraqi government engaged in political reconciliation and did not employ the Iraqi Army and the police for sectarian purposes. In any event, he said, American trainers would not be attached with Iraqi units that go in harm’s way.
“The trainers are going to have to be provided with missions that don’t put them in vulnerable situations,” he said. “Part of what my goal is is that the trainers are not constantly embedded in combat operations.”
Whether such a limited force could effectively influence events in Iraq is an important question. Keeping the part of the force assigned to counterterrorism outside the country raises the issue of whether it could respond in a timely way and without the benefit of the sort of intelligence that is gathered by forces that regularly interact with Iraqi civilians. Nor is it clear how, without keeping some combat forces in the country, the American military might rush to the aid of any trainers if they came under attack.
Mr. Obama acknowledged in the interview that there were “legitimate questions” as to how his concept of a residual force might work, and said he would adjust it if necessary after discussions with senior military leaders.
“As commander in chief, I’m not going to leave trainers unprotected,” he said. “In our counterterrorism efforts, I’m not going to have a situation where our efforts can’t be successful. If the commanders tell me that they need X, Y and Z, in order to accomplish the very narrow mission that I’ve laid out, then I will take that into consideration.”
For all Mr. Obama’s efforts to emphasize an approach that calls for minimal military involvement in Iraq, his plan is in one respect more ambitious than Mrs. Clinton’s. While Mr. Obama said he hoped to withdraw all American combat forces within 16 months of taking office, his plan states that American and allied troops should be prepared to return to Iraq and protect civilians if there were genocidal attacks.
“I do not anticipate that happening, because I think we can execute our withdrawal in an effective way,” he said. “What I am saying is that I as president am obviously going to be mindful of the possibility of humanitarian disaster, and if that were to occur, I am not ruling out that we wouldn’t take steps in concert with other nations — even if it was short term — to ensure that a wholesale disaster did not take place.”
Mr. Obama argued that it was “too speculative” to say if the United States would undertake such action unilaterally or only if allied nations chose to participate.
Other aspects of his policy for the Middle East also remain unclear. Mr. Obama declined to say if he would take military action if Iran did not abandon its presumed nuclear weapons program or if he would settle for a strategy of deterring and containing a nuclear-armed Iran.
“My decision making, with respect to military options versus diplomatic options, a containment strategy versus a strike strategy, is going to be informed by how is that going to impact not just Iran,” he said, “but how is that going to impact the stability of the region and how’s that going to impact our long-term security interests.”
Mr. Obama, a member of the Senate Foreign Relations Committee, visited Iraq in January 2006.
“I’ll be honest with you,” he said. “Part of it is that my schedule is such that the trips would be one or two days and would be centered around the Green Zone.”
He added: “I suspect we will be going back. It probably won’t be before Iowa, realistically speaking.” The Iowa caucuses are scheduled for Jan. 3.