A few days later, on October 19, large formations of Chinese troops, the People’s Volunteer Army (PVA), secretly crossed the border into North Korea. The word volunteer was a calculated political fiction that gave Mao the rhetorical wiggle room to suggest that he was not sending his regular army, and thus had not formally declared war on the United States; this, Mao coyly suggested, was an organic public uprising to defend China’s Communist brethren in neighboring North Korea,
