President Obama has delivered his share of challenging speeches, tackling race and his relationship with the Rev. Jeremiah Wright Jr. in the heat of the 2008 campaign, pitching his health care overhaul plan to a skeptical Congress in September, and, just last week, explaining to an anxious nation his decision to send 30,000 more troops to Afghanistan.
This week, Mr. Obama will face perhaps his most daunting oratorical challenge: accepting a Nobel Peace Prize even as he presides over two wars.
The president heads to Oslo on Wednesday with the additionally awkward burden of receiving the honor even though few Americans -- and perhaps not even Mr. Obama himself -- think he has done anything after less than a year in office to earn the prestigious award.
A Quinnipiac University poll released Tuesday found that 66 percent say the award was undeserved, compared with 26 percent who thought Mr. Obama had earned the prize.
After learning he had been awarded the Nobel Peace Prize in October, he told reporters, "I do not view it as a recognition of my own accomplishments, but rather as an affirmation of American leadership on behalf of aspirations held by people in all nations."
Eric Dezenhall, a Washington media consultant, said it will be difficult to keep the speech from becoming fodder for late-night comedians but that the president will have an opportunity to send the world an important message about what it takes to secure peace in the modern age.
"He should make it clear that not everything he will do will be considered prizeworthy and that sometimes it takes painful, real-world measures to achieve high-minded ideals," Mr. Dezenhall said.
Since Mr. Obama made his carefully worded initial acceptance remarks in the White House Rose Garden, he has encountered global realities that complicate the trip to Oslo even more.
He will step to the podium scarcely a week after announcing his decision to expand the Afghanistan war effort, and less than a week after his vision of a world without the threat of nuclear weapons received a major setback. The Nobel Prize jurors specifically cited that vision when they announced the award in October.
Last weekend, the Strategic Arms Reduction Treaty of 1991 (START) expired before the U.S. and Russia could complete negotiations on a new version. Although both countries have said they intend to honor the expired pact in the interim, the Russians have moved to shutter an American monitoring post that kept track of Russian missile production.
The president's top aides acknowledged this week that Mr. Obama will have to address the Afghanistan conflict as part of his message in Norway.
Press secretary Robert Gibbs said Tuesday that Mr. Obama intends to "address being a president sending troops into battle" as part of his acceptance speech.
Presidential supporters say the address is an important opening for Mr. Obama to remind the world that the U.S. has embarked on a different approach to foreign policy compared with the George W. Bush administration, and that Washington now seeks to tackle transnational threats such as global terrorism in partnership with other nations.
"That kind of honest, frank discussion devoid of sloganeering would represent the dramatic change the Nobel committee supported in its vote for President Obama," said Karen Finney, a Democratic media specialist. She said the president's speech should convey that "the United States is an unapologetic, proud leader and partner on the world stage; the days of cowboy, go-it-alone [diplomacy] are over."
The Nobel panel, consisting of five prominent Norwegian political figures, said in its Oct. 9 announcement of the award that Mr. Obama was chosen because he has "created a new climate in international politics."
"Multilateral diplomacy has regained a central position, with emphasis on the role that the United Nations and other international institutions can play," the committee said. "Dialogue and negotiations are preferred as instruments for resolving even the most difficult international conflicts."
Critics of the president see significant political risk for Mr. Obama.
"I think in this speech, because even the White House said they thought they had been punked, I think he realizes he will need to strive to be humble," said Dana Perino, who served as press secretary under President George W. Bush.
Liz Cheney, a daughter of former Vice President Dick Cheney, told Fox News that she thought the speech would "add to the farce" that Mr. Obama had received the award.
Kevin Madden, a Republican political consultant, said he expects that the president will focus his speech on the sacrifices that real Americans have made in trying to make the world more peaceful.
Mr. Obama has little choice but to highlight the work of others, Mr. Madden said, because "he really hasn't done anything himself in terms of a major peace initiative."
"He should frame the award as a shared achievement and a shared responsibility," Mr. Madden said, "rather than it being all about him."