After failing last year to wrest from Congress a wholesale exemption from many environmental laws, the Pentagon is trying to rally public support for its campaign this year. The Defense Department says that laws such as the Endangered Species Act have interfered with training and other programs in the past. It’s a hassle to have to worry about the well-being of critters and ecosystems, the argument goes. At an environmental forum yesterday at the National Defense University in Washington, D.C., John Keane, a top Army official, said it was hard to proceed with adequate training exercises on military bases because the “Army hosts 170 federally endangered species on 94 installations.” Greenies contend that enviro laws aren’t preventing the military from meeting its goals; they would prefer that the Pentagon seek exemptions on a case-by-case basis, not through a blanket exception. Rep. John Dingell (D-Mich.) seems to agree: “Using the threat of 9/11 and Al Qaeda to get unprecedented environmental immunity is despicable.”