 Complete the following phrase:  The PVA first engaged UN troops on 25 October 1950, with 270,000 PVA troops under the command of General Peng Dehuai, in the Battles of Onjong, Unsan and Pakchon. Following their initial intervention the PVA withdrew, with the UN offensive renewed on 24 November in what was called the Home-by-Christmas Offensive. This triggered PVA to begin another offensive, called the Second Phase Offensive, which pushed the UN forces back in the west while in the east the UN forces were 