From a Wall Street Journal review by Dan Blumenthal of the book by Alex Joske titled “Spies and Lies: How China’s Greatest Covert Operations Fooled the World”:

“Who are our enemies? Who are our friends? This is the revolution’s foremost question,” wrote a young Mao Zedong in 1925. The Chinese Communist Party, of which Mao was then a rising leader, needed to manipulate friends and destroy enemies as it worked to overthrow the Republic of China. The insurgent party was forced to partner with its main rival, the Chinese nationalist party, to fight Imperial Japan. It did so even as it subverted the nationalists from within. According to party history, the CCP eventually prevailed in this deadly contest for power by employing what Mao called his “three magic weapons”: maintaining a strong party, winning armed struggles, and engaging in “united front” operations to infiltrate and co-opt its rivals.