During the height of the debate this spring over ratification of the chemical-weapons treaty, when opponents seemed to be gaining the upper hand, Lt. Gen. Tom McInerney worked his old network of military connections dating back nearly 40 years and produced a letter in support of the weapons ban.

Among the signatories: former national security adviser Colin Powell, former CIA director Stansfield Turner, retired Adm. Elmo Zumwalt Jr. and Gulf War commander Norman Schwarzkopf. The letter scored a direct hit on Capitol Hill, powerfully defusing testimony from former secretaries of defense who were opposing the treaty and providing doubtful Republican senators with the political cover of support from leading lights of the military.

"The single most effective thing was the letter," said a Senate staffer, who requested anonymity. "The letter was a direct counterattack."

McInerney knows something about the most effective time to fire one's weapons. A fighter pilot who served four tours in Vietnam and flew several Cold War missions that were so sensitive he cannot discuss them publicly, McInerney retired from the Air Force in 1994. At the time, he was assistant vice chief of staff and director of the Defense Performance Review, a Clinton administration effort at reengineering the Pentagon.

Since 1996, McInerney, 60, has served as president and chief executive of Business Executives for National Security (BENS), a group of chief executives and managers from some of the nation's best-known companies, including Lockheed Martin Corp., Xerox Corp. and Walt Disney Co. He directs the group's agenda of building a sustainable, effective military while also pushing for arms control and Pentagon efficiency.

McInerney and his wife live in Clifton, where his hobbies include antiquing and reading Tom Clancy novels. He remains very active in the military social life, frequently dining with retired generals and the like. A grown son is a computer programmer in California.

McInerney and BENS are about to embark on their biggest effort yet, lobbying Congress and the White House on behalf of Defense Secretary William Cohen's recently announced Defense Reform Initiative. Cohen's plan calls for cutting 31,000 of 141,000 jobs at the Pentagon and forcing the military to compete with the private sector for support work. He also is calling for two more rounds of base closings, to save a projected $2.8 billion annually.

It'll be a tough sell but one that McInerney said is long overdue. Like American business at the start of this decade, McInerney said, the military has too much overhead, or "tail," in relation to its product line, or "tooth."

"The heart of our problem at the Pentagon today is a business problem," he said.

McInerney likes to cite the example of how the Air Force saved $50 million by switching to FedEx to deliver spare parts to faraway air bases. The service had been spending $135 million using its own in-house system.

"We saved $50 million, but the more important thing is we got better service," he said.

At the height of the Reagan administration defense buildup in the 1980s, the ratio of Pentagon spending on weaponry and support functions such as payroll, health benefits, maintenance and the like stood about 60 to 40, McInerney said.

In today's post Cold War world that balance has shifted to "70 percent support, 30 percent war fighting" -- an untenable ratio, McInerney maintains. To sell Cohen's plan, along with BENS's own Tail-to-Tooth Commission, which operated as a private-sector parallel to the Pentagon streamlining review, McInerney needs to persuade Capitol Hill of the benefits of restructuring and outsourcing.

He reels off examples of those benefits from across the landscape of Corporate America. At Victoria's Secret, he learned that if you order something by phone you will receive it the next day. At Automatic Data Processing, McInerney learned a check for BENS's own employees can be processed for a little more than $1. The Pentagon, by comparison, spends $4.50 to perform the same task. "There's a difference of $1 billion if only the Pentagon would outsource its paychecks," he said.

But McInerney has been in Washington long enough to know how to play the political game. "We'll find out where the wiggle room is," he said. "Being right in this town doesn't get you anywhere. We know we've got to be practical."

It's this ability, to focus on the problem and provide a visitor with razor-sharp examples one after the other and to do it all in a low-key, persuasive manner, that makes McInerney a disarmingly effective salesman, say those who have come into contact with him.

"He's a persistent guy, that's for sure," said BENS member Paul Lombardi, chief executive of DynCorp, a Reston company that does a lot of government outsourcing work.

John Holum, director of the Arms Control and Disarmament Association, said McInerney's modesty is a refreshing change of pace in a town where large egos are a dime a dozen.

"In Washington, the standard ratio is people spend 20 percent of their time doing things and 80 percent taking credit," said Holum. "With Tom, it's the other way around. If he says he is going to do something, you don't even have to give it another thought."

Still, as McInerney acknowledges, the task of persuading Congress to close more military bases and privatize more Pentagon functions is not an easy one. In fact, it could be about as difficult as flying reconnaissance missions deep in enemy airspace. RESUME Thomas G. McInerney

Age: 60 Lives: Clifton, Va. Career highlights: Vice president of command and control for Loral Defense Systems, 1994 to 1996. Thirty-five-year career in the Air Force. Commissioned as a second lieutenant in 1959, did four tours in Vietnam, flew spy missions during the Cuban Missile Crisis, commander of the Third Tactical Fighter Wing at Clark Air Force Base in the Philippines, commander of the 313th Air Division, Okinawa, vice commander in chief, Air Force in Europe, commander 11th Air Force, Alaska. Retired from military service as the assistant vice chief of staff and director of the Defense Performance Review. Education: Bachelor of Science from the U.S. Military Academy at West Point in 1959. Master's degree in International Relations from George Washington University in 1972. Also completed Armed Forces Staff College in 1970 and the National War College in 1973. Personal: Married to Mona; one adult son, Tom Jr., who is a computer programmer with Sony in Southern California. Hobbies: Skiing at Telluride, Colo.; collecting Georgian and Victorian antiques; golf. Car: 1996 Ford Taurus (always buys American) Favorite airplane: F15 Favorite movie: "Doctor Zhivago." Most recent movie: "Air Force One." Favorite author: Tom Clancy Most memorable career moment: Directing the military's support of the Exxon Valdez oil spill while commander of the Alaskan command.