NEW YORK – US President Barack Obama had an existential policy crisis in his fifth speech to the United Nations on Tuesday, voicing aloud his frustrations with the seemingly contradictory goals of domestic demands for American global leadership and his duty to respect the nation’s weariness of war; and with anti-Americanism abroad and foreign calls that the United States – with all its moral weight and military might – defend the helpless victims of tyrants around the world.His answer to those frustrations, to the skeptics of moderation and to his harshest critics abroad, including Russian President Vladimir Putin, was to equate the fundamental interests of the United States with those of the international community. “I believe that America is exceptional – in part because we have shown a willingness, through the sacrifice of blood and treasure, to stand up not only for our own narrow self-interest but for the interests of all,” Obama said.But the Syrian crisis, he said, highlighted for him a contradiction that has plagued the US for decades: “The United States is chastised for meddling in the region, and accused of having a hand in all manner of conspiracy,” and at the same time “is blamed for failing to do enough to solve the region’s problems and for showing indifference toward suffering Muslim populations.”That has been compounded by American public opinion, Obama said, which has consistently been against intervening in the Syrian crisis, even after video footage flooded screens across the country showing hundreds of children suffocating to death from gas.The speech was further evidence that the president’s signature is contemplation, measured thought and deliberation more than grand declarations, doctrines and warnings.And yet doctrine did emerge, in perhaps the clearest foreign policy list Obama has ever delivered.During the remainder of his presidency, Obama said, the US would be prepared “to use all elements of our power, including military force, to secure these core interests in the region.”“We will confront external aggression against our allies and partners, as we did in the Gulf War,” he said. “We will ensure the free flow of energy from the region to the world... We will dismantle terrorist networks that threaten our people... and finally, we will not tolerate the development or use of weapons of mass destruction.”After building his political career on a policy of disentanglement from the miring problems of the Middle East, and hoping throughout his first term to manage a policy pivot to Asia proper, the president said forcefully that the US “will be engaged in the region for the long haul.”“In the near term, America’s diplomatic efforts will focus on two particular issues: Iran’s pursuit of nuclear weapons, and the Arab-Israeli conflict,” Obama said. “They have been a major source of instability for far too long, and resolving them can help serve as a foundation for a broader peace.”Humbled by wars past, the president seems to believe, as he stated during the Syrian crisis, that “right is might, not the other way around” – and that force must be used to build a peace both deep and broad.That policy was outlined extensively in 2009, only months into his presidency, when Obama accepted the Nobel Prize for peace.“I face the world as it is, and cannot stand idle in the face of threats to the American people,” he said then. “For make no mistake: Evil does exist in the world. A nonviolent movement could not have halted Hitler’s armies. Negotiations cannot convince al-Qaida leaders to lay down their arms.”“To say that force is sometimes necessary is not a call to cynicism,” he added. “It is a recognition of history, the imperfections of man and the limits of reason.”Indeed, the president will face the limits of reason as he settles squarely on two of the world’s most maddening problems.