Cho Seung-hui does not stand for America's students, any more than Dylan Klebold and Eric Harris did when they slaughtered 13 of their fellow high-school students at Columbine in 1999. Such disturbed people exist in every society. The difference, as everyone knows but no one in authority was saying this week, is that in America such individuals have easy access to weapons of terrible destructive power. Cho killed his victims with two guns, one of them a Glock 9mm semi-automatic pistol, a rapid-fire weapon that is available only to police in virtually every other country, but which can legally be bought over the counter in thousands of gun-shops in America. There are estimated to be some 240m guns in America, considerably more than there are adults, and around a third of them are handguns, easy to conceal and use. Had powerful guns not been available to him, the deranged Cho would have killed fewer people, and perhaps none at all.