"World Governments Recognize Tibet: The Tibetan Perspective
International law states that recognition can occur by explicit or implicit acts including treaties, negotiations, and diplomatic relations. Mongolia and Tibet signed a formal treaty of recognition in 1913. Historically, Nepal and Tibet had peace treaties. Tibetºs independence was also confirmed at the Treaty of Simla (1914) which was concluded by Tibet and British India. In 1949, Tibet maintained diplomatic, economic, and cultural relations with such countries as Nepal, Sikkim, Mongolia, China, British India, and to some extent, Russia and Japan. Further, Nepal maintained an Ambassador in Lhasa and told the U.N. in 1949 that it conducted international relations with Tibet. In fact, Britian, Bhutan, India, and even China also maintained diplomatic missions in Tibet's capitol, Lhasa. The Tibetan Foreign Office conducted talks with President Franklin D. Roosevelt when he sent representatives to Lhasa to discuss the allied war effort against Japan during World War II. In 1950, El Salvador formally requested that China's aggression against Tibet be placed on the agenda of the U.N. General Assembly. The issue was not discussed. However, during four U.N. General Assembly debates on Tibet (1959, 1960, 1961, & 1965), many countries (e.g., Philippines, Nicaragua, Thailand. United States, Ireland) openly stated that Tibet was an independent country illegally occupied by China. In fact, the U.N. passed three resolutions (1959, 1961, & 1965) concerning Tibet stating that Tibetans were deprived of their inalienable rights to self-determination. Even Mao Zedong during the Long March admitted that Tibet was an independent country when he passed through the border regions of Tibet remarking, "This is our only foreign debt, and some day we must pay the Mantzu (sic) and the Tibetans for the provisions we were obliged to take from them." Tibetans clearly constitute a people under international law, as described, for instance, by the UNESCO International Meeting of Experts on Further Study of the Concept of the Rights of Peoples. They are a distinct people and fulfill all the characteristics of this concept: commonality of history, shared language, culture, and ethnicity. " Source -http://www.rangzen.com/history/views.htm
Now there are divergent views on whether Tibet was a prt of China or not. But the truth is that before the Mongol invasion in 13th century, Tibet n China were never under the same ruler. And if China didnt invade Tibet, then what was the battle in Chamdo in 1950? A cultural exchange festival?
And I guess thousands of Tibetans that migrated to India in 1950s and set up a govt. in exile just for fun! I mean one day they got up from sleep and said, "Hey I know what. Gather all the villagers and lets go to India".