“We must begin by acknowledging the hard truth,” Mr. Obama said. “We will not eradicate violent conflict in our lifetimes. There will be times when nations — acting individually or in concert — will find the use of force not only necessary but morally justified.”

He said he accepted the award with “deep gratitude and great humility,” conceding it could be seen as premature.

“I would be remiss if I did not acknowledge the considerable controversy that your generous decision has generated. In part, this is because I am at the beginning, and not the end, of my labors on the world stage,” Mr. Obama said. “Compared to some of the giants of history who have received this prize — Schweitzer and King, Marshall and Mandela — my accomplishments are slight.”

He added, “But perhaps the most profound issue surrounding my receipt of this prize is the fact that I am the commander in chief of a nation in the midst of two wars. One of these wars is winding down.”

“We lose ourselves when we compromise the very ideals that we fight to defend. And we honor those ideals by upholding them not when it is easy, but when it is hard.”

The president conceded that there was “a deep ambivalence about military action today,” which he said was rooted in “a reflexive suspicion of America, the world’s sole military superpower.” But he offered a forceful defense of the United States, saying that the lessons of history should ease those suspicions.

“Whatever mistakes we have made, the plain fact is this,” Mr. Obama said. “The United States of America has helped underwrite global security for more than six decades with the blood of our citizens and the strength of our arms.”

“Let us reach for the world that ought to be that spark of the divine that still stirs within each of our souls.”

“A decade into a new century, this old architecture is buckling under the weight of new threats. The world may no longer shudder at the prospect of war between two nuclear superpowers, but proliferation may increase the risk of catastrophe. Terrorism has long been a tactic, but modern technology allows a few small men with outsize rage to murder innocents on a horrific scale.”

“I do not bring with me today a definitive solution to the problems of war. What I do know is that meeting these challenges will require the same vision, hard work and persistence of those men and women who acted so boldly decades ago. And it will require us to think in new ways about the notions of just war and the imperatives of a just peace.”

The president said that the United States’ commitment to global security “will never waver.”

“But in a world in which threats are more diffuse and missions more complex, America cannot act alone. This is true in Afghanistan. This is true in failed states like Somalia, where terrorism and piracy is joined by famine and human suffering. And sadly, it will continue to be true in unstable regions for years to come.”

He had been on the ground for only a few hours when a Norwegian reporter asked Mr. Obama how he could use the prize to counter criticism that the award was premature.

“I have no doubt that there are others who may be more deserving,” Mr. Obama said. “My task here is to continue on the path that I believe is not only important for America, but important for lasting peace and security in the world.”

The president said his goals of pursuing a world free of nuclear weapons, addressingclimate change and stabilizing Afghanistan would ultimately define his success.

“The goal is not to win a popularity contest or to get an award — even one as esteemed as the Nobel Peace Prize,” Mr. Obama said. “The goal is to advance American interests, make ourselves a continuing force for good in the world — something that we have been for decades now.”

He added: “And If I’m successful in those tasks, then hopefully some of the criticism will subside, but that’s not really my concern. And if I’m not successful, then all the praise and the awards in the world won’t disguise that fact.”

http://www.nytimes.com/2009/12/11/world/europe/11prexy.html?hp=&pagewanted=print