Tiananmen, 20 Years Later

Plainclothes policemen shield themselves with umbrellas as they work undercover opposite to Tiananmen Square in Beijing, Thursday, June 4, 2009. Chinese police aggressively deterred dissent on the 20th anniversary of the crackdown on democracy activists in the square, ignoring calls from Hillary Rodham Clinton and even Taiwan's China-friendly president for Beijing to face up to the violence.

Credit: AP Photo/Elizabeth Dalziel