This is perhaps the most militarized Buddhist enclave in the world. Perched above 10,000 feet in the icy reaches of the eastern Himalayas, the town of Tawang is home to one of Tibetan Buddhism's most sacred monasteries and the site of a massive Indian military buildup. A road sign on the northern edge of town helps explain the reason for all the fear and the fury: The border with China is just 23 miles away; Lhasa, the Tibetan capital, 316 miles; and Beijing 2,676 miles. Tawang is a flashpoint in relations between the world's two most populous nations. It is the focus of China's most delicate land-border dispute, a conflict rooted in Chinese claims of sovereignty over all of historical Tibet. In recent months, both countries have stepped up efforts to secure their rights over this rugged patch of land. China tried to block a $2.9 billion loan to India from the Asian Development Bank because part of the loan was slated for water projects in Arunachal Pradesh, the state that includes Tawang. It was the first time China had sought to influence the territorial dispute through a multilateral institution. Then the chief of India's air force, now retired, announced that the Indian military was deploying extra troops and fighter jets in the area. The growing belligerence has soured relations between the two Asian giants and has prompted one Indian military leader to declare that China has replaced Pakistan as India's biggest threat. The roots of the conflict go back to China's territorial claims to Tibet. Not only does the Dalai Lama, the exiled spiritual leader of the Tibetans, live in the foothills of the western Himalayas with the blessing of the Indian government, but China insists that this swath of northeast India has historically been part of Tibet, and thus should be part of China. Tawang is a forested area of white stupas and steep, terraced hillsides that is home to the ethnic Monpa people, who practice Tibetan Buddhism, speak a language similar to Tibetan and once paid tribute to rulers in Lhasa. China refuses to recognize the boundary between India and Tibet set by Britain in 1914. 'The entire border is disputed,' said Ma Jiali, an India scholar at the China Institutes of Contemporary International Relations, a government-supported think tank in Beijing. 'This problem hasn't been solved, and it's a huge barrier to China-India relations.' 