Two days after he delivered his Afghanistan address last week at the United States Military Academy at West Point, Mr. Obama sat down in the Oval Office with two speech writers, Ben Rhodes and Jon Favreau, and began to offer an outline for what he would like to say in Oslo.

Mr. Obama is the third sitting American president to be awarded the peace prize. A student of history, he read the lecture of Theodore Roosevelt, who won the award in 1906 for his role in bringing an end to the war between Russia and Japan. He also studied the words of Woodrow Wilson, who sent a telegram to the committee  he was ill and could not attend a ceremony  for his 1919 award in recognition of his 14-point peace program for ending World War I.

With so few former presidents to seek guidance from, aides said, Mr. Obama also spent time looking back at the speech of George C. Marshall, who was awarded the prize in 1953 for helping to rebuild the post-World War II world through the plan of economic aid that bears his name. Mr. Obama also was intrigued by the lectures of more recent honorees, aides said, including Mr. Mandela in 1993 and Dr. King in 1964.

The lessons of history, though, provided only a limited amount of instruction, considering that Mr. Obama’s circumstances are starkly different than those of previous winners. So in addition to explaining his strategy for Afghanistan  outlining why war is necessary to bring peace  the president’s advisers said they will reprise the words of humility that Mr. Obama delivered on Oct. 9, hours after learning he had won the award.

“It’s not necessarily an award he would have given himself,” Mr. Axelrod said. “In that sense, it poses a challenge, but thinking through these issues is not burdensome. He spends a lot of time thinking about how you promote a more peaceful and secure world, about the appropriate use of power and about the value and importance of diplomacy.”

To minimize his time away from Washington, where a vigorous debate over health care and Afghanistan is under way on Capitol Hill, Mr. Obama is leaving the White House on Wednesday evening and flying overnight to Oslo. He will formally enter the history of the 108-year-old Nobel prize when he delivers his lecture in a ceremonial room of Oslo City Hall, which offers a view of the picturesque bay of Oslofjorden.

It was then, aides said, they realized that they would not be able to tailor the setting of the lecture in the way they usually do to project Mr. Obama exactly how they wish.

When presidents deliver their most important speeches, like Mr. Obama’s April address on nuclear threats from the central square of Prague or his June speech to the Muslim world from Cairo University, the White House choreographs the backgrounds, camera angles and crowds. But in this case the venue, like the award itself, is something that this president cannot control.