The Pentagon told Congress Tuesday that at least 567 of the 2,170 MIA cases still on the books from the Vietnam War should be considered hopeless. Though the Defense Department has previously acknowledged that some cases can never be resolved, this is the first time a specific number has emerged. The finding "will no doubt fan the flames of conspiracy theories embraced by a fervent minority that seeks to keep the MIA issue alive," says TIME Defense correspondent Mark Thompson. "We should bear in mind, however, that there are many more people unaccounted for from the Korean War and World War II. The great majority of Americans, both in and out of uniform, want closure on the MIA issue."