Citing the specter of impending war in Iraq, the Bush administration asked Congress this week to exempt the Pentagon from a wide range of environmental laws. Congress rejected a similar request last year, but now, war looms and Republicans control both the House and the Senate. Under the plan proposed by the administration, the Pentagon would be exempt from the Clean Air Act, the Endangered Species Act, the Superfund law, the Resource Conservation and Recovery Act, and the Marine Mammal Protection Act when the laws interfered with training — broadly defined to include such activities as driving vehicles on military bases or from one site to another. The plan would also grant states greater leeway in meeting federal clean-air standards if military equipment such as jet fighters and tanks were adding to overall air pollution. Critics say the plan is unnecessary because there is no evidence that environmental protections adversely affect military preparedness.