As part of the Defense Department’s ongoing effort to exempt the U.S. military from environmental regulations, the Pentagon’s Paul Wolfowitz has called on military service heads to provide examples of situations in which President Bush should invoke national security to trump eco-protections by fiat. In a memo to the chiefs of the Armed Forces, Wolfowitz, who is deputy defense secretary, wrote, “it is time for us to give greater consideration to requesting such exemptions” from the president, who has the authority to issue them but has never done so in U.S. history. Pentagon spokesperson Glenn Flood acknowledged the memo but said the exemptions could only be called for in a “dire, critical situation.” Critics of the exemptions note that, because they are granted by the president, they are not subject to any kind of challenge or review.