Former President Robert Mugabe, left, and  President Xi Jinping from China. File Pic. BEIJING — Recent history offers sobering lessons to China’s Communist Party following its decision to allow President Xi Jinping to rule indefinitely. For millennia, one-man rule for life was standard under kings and emperors. But from Zimbabwe to Iraq to North Korea, modern autocrats often blunder into economic stagnation, political dysfunction and war. “There is a tendency for erratic and sometimes unwise policy choices,” said Erica Frantz, a Michigan State University political scientist who studies dictatorships, in an email. Those include “more belligerent foreign policy” and greater likelihood of war. On paper, deleting term limits on Xi’s ceremonial post as president from China’s…