President Barack Obama made one of the most important foreign policy statements of his presidency last week, when he told the Australian parliament in Canberra that he would be sending 2,500 US Marines to Australia. The modest force will be based in Darwin, a port city in northern Australia that was bombed by the Japanese in 1942. In fact, more bombs fell on Darwin than fell on Pearl Harbor a few months earlier. The attack on Darwin and the massive military assistance later provided by the US was the start of a military and political partnership that has lasted for more than 70 years. The role that had once been played by Great Britain was taken over by the US. It has stayed that way, though the British used the Australian deserts to test their atomic weapons in the 1950s.

Although the presence of 2,500 US marines in Australia does not alter the strategic balance in Asia, their presence, and the president's words, send a powerful message to China. So far, as expected, the Chinese have said they don't like it. What the president actually said was: "Here is what the region must know. As we end today's wars, I have directed my national security team to make our presence and missions in the Asia Pacific a top priority. The United States is a Pacific power and we are here to stay." Adding a little heft to his words was the fact that the president himself is a Pacific American, despite the naysayers, having been born in Hawaii and spending part of his childhood in Indonesia.

There could not be a clearer and more direct statement of policy. Around the Asian Pacific rim, the statement was warmly received. The awesome rise of China as an economic power has deep political and military ramifications that many nations, from India to the Philippines, find worrisome. So does Australia, which is locked in a tight economic embrace with China that Australians find immensely profitable but at the same time worrying. How close is too close? What does China intend to do with its new blue water navy? If Beijing says it intends to be master in its own backyard, what happens to the large US naval presence that has been in Asian Pacific waters since World War 11, and has long been considered part of the bedrock defense of the western world? President Obama gave a definitive answer to that question by saying, in effect that "we are here and we intend to stay here."

The president made a second decisive move last week by sending Secretary of State Hillary Clinton next month to Yangon, Myanmar, perhaps better known as Rangoon, Burma. She is the first secretary of state and the highest-ranking American to visit the country in fifty years. Myanmar has been ruled for decades by a military regime that much of the world has cordially despised. And sometimes not so cordially. But that long period seems to be coming to an end as a new cast of leaders begins to ease the old tight controls.

In the 1960s, and in the following decades, the Burmese military made China its primary ally and economic partner, a partnership in which Burma was caught in a political and economic time warp circa 1948, the year Burma got its independence from Great Britain. That was also the year that Burma's great national hero, Aung San, was assassinated, leaving behind a young daughter, who the world has come to know as Daw Aung San Suu Kyi. A woman of great strength of character, determined to fulfill her father's ambitions as national leader, she has been under effective house arrest for more than 20 years.

Despite her years of house arrest, Aung San Suu Kyi, is an enormously popular figure in her own right, recognized as the head of the opposition to the military regime, refusing to cooperate politically. Last week, she moved the country onto a new path when she agreed to rejoin the country's political system, a decision that though weeks in the making, opened a new era with remarkable speed as Obama announced his decision to send Clinton to Yangon.

The confluence of events, announcing the deployment of marines to Australia along with the strong statement about the US remaining a Pacific power, and then sending Clinton to Burma, a long-time China client, sends a clear message to China that the US is in the Pacific for good, and is not backing down in the face or growing Chinese power. Let China make of it what it will. Foreign policy is turning opt to be Obama's strong suit.

William M. Stewart, a former U.S. Foreign Service officer and Time magazine correspondent, lives in Santa Fe.