In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Q: Who commanded the force that was sent to defeat the Western Liao, led by an usurper who had previously been the khan of the Naiman confederation?, Context: Kuchlug, the deposed Khan of the Naiman confederation that Temujin defeated and folded into his Mongol Empire, fled west and usurped the khanate of Qara Khitai (also known as the Western Liao, as it was originally established as remnants of the Liao dynasty). Genghis Khan decided to conquer the Qara Khitai and defeat Kuchlug, possibly to take him out of power. By this time the Mongol army was exhausted from ten years of continuous campaigning in China against the Western Xia and Jin dynasty. Therefore, Genghis sent only two tumen (20,000 soldiers) against Kuchlug, under his younger general, Jebe, known as "The Arrow".
A:
Jebe