The Trump administration stepped up its offensive against China with new measures that it said were aimed at rooting out espionage and national security risks at America’s colleges and universities. At a press conference held on the White House lawn Friday afternoon, President Trump said the U.S. would bar Chinese nationals who have an affiliation with the People’s Liberation Army, or PLA, from receiving visas to study or conduct graduate or post-doctoral research in the United States. In a proclamation released later, the President said the measures were aimed at stopping China from engaging in a “wide-ranging and heavily resourced campaign to acquire sensitive United States technologies and intellectual property” intended to bolster the Chinese military. Undergraduate study by Chinese in the U.S. would not be affected by the new restrictions. The move, though, was quickly rebuked by college administrators who warned that the Trump administration’s tactics — in co