China's active presence in Tibet preceded a much more dangerous confrontation between India and China. Successive Chinese governments had rejected the Sino-Indian border dictated by the British Empire in the early 20th century, called the McMahon Line. As China built outposts along what China thought to be its borders, India built more outposts in the disputed area to drive out the Chinese, in what would be known as the Forward Policy. Charges and countercharges of border violation and aggression were exchanged along the frontier. On September 9, a few days before his departure for the U.S., Janos Kadar of Hungary attempted to mediate the disputes between China and India, hoping to appeal to his friendly relations in both parties. Khruschev and Alexander Dubček of Czechoslovakia also appealed to China and India. However, China's reaction to the Soviet, Hungarian, and Czechoslovakian appeal for peaceful coexistence with the West and India was not seen as encouraging; and the fallout of the tensions along the Himalayas caused worldwide speculation over the Warsaw Pact-Chinese alliance, which was based on common ideological, political, and military interests.