WHY IS THE U.S GOVERNMENT PICK AND CHOOSE WHEN IT COME TO OTHER COUNTRIES CONFLICT?

After the United States won the Cold War against the Soviet Union during the 1940 throughout 1990s, it took the wheel and drives the world to it political correction, where it want the rest of the world to participate in it. We have seen many invasion that our government had done, and continue to do so as part of controlling the world, show off our military power, and gaining some economic interest. At the beginning of this month the Dalai Lama visited the United State, and spoke in many universities. I happened to follow most of his speech, and begin to think a lot about his country Tibet, and what action the U.S government has taken or where they stand now toward the Tibet, and Chine issue. The conflict between the People Republic of China and Tibet, is kind of the general knowledge, but for those who don't know, I will give a little background history. Tibet was an independent country until 1949, when the communist government under Mao Zedong invited it as a part of China. During the invention the U.S government was against the communist government, so it supported the Tibetans' believes of being free from the communist. But somehow in the blue, the relationship between People Republic of China, and the U.S grew stronger, and now the voice of Tibetans citizens of wanting their freedom of religion participation, and to be independent from China is stronger, but there is not any The U.S government has take. Do you thing the reason is because we will lose relationship with China? or is because the land of Tibet has nothing we can get from it?