 Complete the following phrase:  The Qianlong emperor of China was committed to an expansionist policy in Central Asia and saw the Russian empire as a potential rival, making for difficult and unfriendly relations between Beijing and Saint Petersburg. In 1762, he unilaterally abrogated the Treaty of Kyakhta, which governed the caravan trade between the two empires. Another source of tension was the wave of Dzungar Mongol fugitives from the Chinese state who took refuge with the Russians. The 