Since Sept. 11, the Bush administration has claimed that strict environmental laws are hindering oil and gas exploration in the West — thereby compromising national security by forcing ongoing dependence on foreign energy sources. But a new federal study undermines that claim by showing that most oil and gas reserves on Western federal lands could be explored under standard government leases. In a finding described by Interior Assistant Secretary Rebecca Watson as “unexpected,” 57 percent of oil and 63 percent of gas in five major geological basins on federal land are not subject to any kind of special usage restrictions. Only 15 percent of the oil and 12 percent of gas is “totally unavailable” — i.e., in wilderness areas or national parks. Environmentalists said the findings suggested that there is no need to ease environmental protection on public lands. But the report could backfire for greens: Diemer True, chair of the Independent Petroleum Association of America, said, “Now we know that these resources in the inter-mountain West should be available for leasing, we need to make sure it happens.”