Speaking at the U.S. Naval Academy in Annapolis, Md., Clinton said emerging regions, "especially the Asia Pacific, are becoming key drivers of global politics and economics."
Today, she said, "no totalitarian empire threatens the world. But new actors are wielding increasing influence in international affairs."
"Still, amidst all this change, two constants remain. First, a just, open, and sustainable international order is still required to promote global peace and prosperity. And second, while the geometry of global power may have changed, American leadership is as essential as ever."
Clinton noted North Korea's impending launch of a long-range missile in violation of U.N. Security Council resolutions would "put its neighbors and region at risk."
"This launch will give credence to the view that North Korean leaders see improved relations with the outside world as a threat to the existence of their system," she said. "And recent history strongly suggests that additional provocations may follow."
In a more positive vein, she noted Myanmar -- formerly known as Burma -- "offers a meaningful opportunity for economic and political progress."
"For decades, that Southeast Asian nation has been locked behind an authoritarian curtain while many other countries in the region made successful transitions to vibrant democracies and open markets," she said. "The United States, supporting these transitions, has been one of our defining efforts in the Asia Pacific from South Korea to the Philippines to Thailand to Indonesia."
And, she said, "Today's China is not the Soviet Union."
"We are not on the brink of a new Cold War in Asia," the secretary of state said.
"Geopolitics today cannot afford to be a zero-sum game. A thriving China is good for America and a thriving America is good for China, so long as we both thrive in a way that contributes to the regional and global good. Let me go one step further. We will only succeed in building a peaceful, prosperous Asia Pacific if we succeed in building an effective U.S.-China relationship."