In the decade after World War II, 2 million veterans went to college on the new GI Bill, and almost all of them graduated and went on to power the post-war economic boom. This fall, tens of thousands of Iraq and Afghanistan War veterans are enrolled in colleges and universities across the country, courtesy of the GI Bill. But almost all of them — 88 percent — will drop out by next summer, feeling isolated and frustrated in an alien culture. Before they disappear from campus, they will contribute to another dismaying statistic: student veterans are seven times more likely to attempt suicide than their civilian counterparts.