As I have arguing in the '
Why China might be a better superpower ' thread, China has always been a expansionist power throughtout its 2500yrs history, whenever it has been relatively stronger than its neighbors. The slogan of 'Peaceful rise of China' is just an misleading propaganda, when the evidence is exactly opposite.
Along with the occupation of Tibet, the Chinese People's Liberation Army occupied eight western Tibetan enclaves under Bhutanese administration. A Chinese map published in 1961 showed China claiming territories in Bhutan, Nepal and the kingdom of Sikkim (now a state of India). Incursions by Chinese soldiers and Tibetan herdsmen also provoked tensions in Bhutan. Imposing a cross-border trade embargo and closing the border, Bhutan established extensive military ties with India. During the 1962 Sino-Indian War, Bhutanese authorities permitted Indian troop movements through Bhutanese territory.However, India's defeat in the war raised concerns about India's ability to defend Bhutan. Consequently, while building its ties with India, Bhutan officially established a policy of neutrality. According to official statements by the King of Bhutan to the National Assembly, there are four disputed areas between Bhutan and China. Starting from Doklam in the west, the border goes along the ridges from Gamochen to Batangla, Sinchela, and down to the Amo Chhu. The disputed area in Doklam covers 89 square kilometres (km2) and the disputed areas in Sinchulumpa and Gieu cover about 180 km2
Map of Bhutan showing border with China as of 2010
Until the 1970s, India represented Bhutan's concerns in talks with China over the broader Sino-Indian border conflicts. Obtaining membership in the United Nations in 1971, Bhutan began to take a different course in its foreign policy. In the U.N., Bhutan, incidentally alongside India, voted in favour of the PRC filling the seat occupied by the ROC and openly supported the "One China" policy. In 1974 in a symbolic overture, Bhutan invited the Chinese ambassador to India to attend the coronation of Jigme Singye Wangchuk as the king of Bhutan. In 1983, the Chinese Foreign Minister Wu Xueqian and Bhutanese Foreign Minister Dawa Tsering held talks on establishing bilateral relations in New York. In 1984, China and Bhutan began annual, direct talks over the border dispute.
In 1998, China and Bhutan signed a bilateral agreement for maintaining peace on the border. In the agreement, China affirmed its respect for Bhutan's sovereignty and territorial integrity and both sides sought to build ties based on the Five Principles of Peaceful Co-existence. However, China's building of roads on Bhutanese territory, allegedly in violation of the 1998 agreement, has provoked tensions. In 2002, however, China presented what it claimed to be 'evidence', asserting its ownership of disputed tracts of land; after negotiations, an interim agreement was reached.