With such a small force, the invading Mongols were forced to change strategies and resort to inciting internal revolt among Kuchlug's supporters, leaving the Qara Khitai more vulnerable to Mongol conquest. As a result, Kuchlug's army was defeated west of Kashgar. Kuchlug fled again, but was soon hunted down by Jebe's army and executed. By 1218, as a result of defeat of Qara Khitai, the Mongol Empire and its control extended as far west as Lake Balkhash, which bordered the Khwarezmia (Khwarezmid Empire), a Muslim state that reached the Caspian Sea to the west and Persian Gulf and the Arabian Sea to the south.