WASHINGTON, Dec 16 (Reuters) – The U.S. State Department on Friday launched its long-planned "China House" unit, an internal reorganization to help expand and sharpen its policymaking toward its top geopolitical rival. Secretary of State Antony Blinken in May announced the creation of China House, calling it a department-wide, integrated team that would coordinate and implement U.S. policy across issues and regions. "The scale and the scope of the challenge posed by the People's Republic of China will test American diplomacy like nothing we've seen before," Blinken said in May. Blinken on Friday presided over the official opening of the…