WASHINGTON — The auto industry is facing one of its toughest political battles in years as shifts in the political and business landscape have eroded its defenses against stricter fuel economy standards.

Congressional Democrats and environmental groups have new allies in the fight to mandate higher vehicle mileage, including a coalition of business executives and retired military leaders. President Bush's support of higher standards also has hampered Detroit's efforts to fend off new rules. Increasingly, the war in Iraq and related concerns over U.S. dependence on foreign oil are changing the dynamics of the debate.

"Something happened in the last five years, most likely the war in Iraq," said Mike Jackson, chairman and chief executive of AutoNation, the nation's largest chain of dealerships. "People see the connection that we went to war for the first time over oil, we stayed around over oil and we're back there over oil."

Sen. Byron Dorgan, D-N.D., said the auto industry is confronted by a "sea change" in Washington, where lawmakers equate action on fuel economy with the issues of global warming, high gasoline prices, foreign oil dependence and the war in Iraq.

Attracting support from other senators on fuel-economy changes is "not an uphill push anymore," Dorgan said.

Bush yesterday toured two Kansas City, Mo.-area auto plants to promote his plan to reduce gasoline consumption by 20 percent over the next decade. Speaking to workers at a Ford plant, Bush said he was looking forward to working with both Democrats and Republicans to reach his goals.

Bush also framed the issue in a national security context: "When you make one of these cars, you're helping the national security of the country," he said.

Bush's plan also includes raising fuel-economy standards by 4 percent a year over the next 10 years. Last week, Dorgan and Sen. Larry Craig, R-Idaho, proposed legislation that would do much the same. But while Bush's plan would give the administration the power to control the process through the National Highway Traffic Safety Administration, the proposals in Congress would write any new rules into law. Democrats and environmental groups say they fear that the administration's scenario would give automakers a chance to weaken new rules.

Gloria Bergquist, vice president of the Alliance of Automobile Manufacturers, said leaving the rule-making to NHTSA would allow changes to be based on "science, not arbitrary numbers." She said NHTSA would balance technological feasibility, safety, affordability, consumer demand and jobs.

Automakers have resisted increases in fuel economy, saying changes would cost them billions of dollars.

"The automakers are rightfully concerned with cost," said retired Marine Corps Commandant Gen. P. X. Kelley, a member of the Energy Security Leadership Council. "We understand that, but there has to be a compromise somewhere. They have not done much willingly so we have to put the pressure on them to do it."

Business executives and former military leaders formed the council, whose members include Frederick Smith, chairman and chief executive of FedEx; retired Adm. Dennis Blair, former commander in chief of U.S. Pacific Command; and Herbert Kelleher, chairman of Southwest Airlines.

"We are in such a threatening and emergent situation that frankly we have to start looking at the welfare of the country as a whole, and a tremendous weakness is our dependence on oil," Kelleher said. The auto industry should receive "substantial incentives" to retool factories to develop more fuel-efficient vehicles, such as hybrids, Kelleher said.

Jackson, of AutoNation, said higher gasoline taxes would also help.

"Fuel economy right now in the U.S. is right next to cup holders in consideration," he said. "You have to have a component that entices or encourages consumers to buy more fuel-efficient vehicles as it's done in Europe. To just raise fuel economy without a consumer component will not work."

Staff reporter Michael Fletcher contributed to this report from Claycomo, Mo.