BRUNSWICK – The closing of Brunswick Naval Air Station would leave New England without an active-duty military airfield, something critics say would make the densely populated Northeast vulnerable to enemy attacks in the future.

In terms of cost and convenience to the Defense Department, it might make sense to move all of Brunswick’s surveillance and transport planes to Jacksonville, Fla.

“But from a defending-the-nation point of view, it doesn’t make any sense at all,” said Loren B. Thompson, an analyst with the Washington-based Lexington Institute.

Jay Korman, a naval analyst with DFI International in Washington, agreed that shuttering the base could make the region more susceptible. But given the global situation, it makes sense to take resources from the Northeast and put them where there’s a greater need, he said.

“There’s no question the military presence in the Northeast has withered,” Korman said. “The department’s thinking is you can consolidate activities in single locations, and unfortunately it happens to be in the South and the West.”

Five rounds of base closings since 1988 have stripped New England and New York of all other active military air bases, leaving only guard and reserve bases.

The ones that have closed include Pease Air Force Base in New Hampshire (1991); Loring Air Force Base in Maine (1994); Plattsburgh and Griffiss Air Force bases in upstate New York (1995); and South Weymouth Naval Air Station in Massachusetts (1997).

The last one standing, Brunswick Naval Air Station, is home to P-3 Orions whose mission includes surveillance work over the North Atlantic.

Rick Tetrev, a 23-year Navy veteran who was once second-in-command at the Brunwsick base, thinks it is poor military strategy to place all the planes in one location in Jacksonville because they could be wiped out in a single hurricane or enemy attack.

The closure also means that the P-3s will no longer routinely patrol the shipping lanes of the North Atlantic to serve as deterrents on the open ocean. That, he added, is bad policy when there are concerns about enemies using ocean vessels to launch missiles at the United States or even to transport terrorists using shoulder-held missile launchers.

“We live in the most powerful country in the world and you’re telling me we can’t afford to have an airfield in all four corners of our country? That’s beyond comprehension,” he said. “Are we going to have the Canadians protect us in the Northeast?”

If the base closure stands, the Defense Department plans to move all aircraft – there are now 37 P-3 Orions and three C-130 Hercules transport planes – to the Jacksonville Naval Air Station. The base closing process should be completed by 2011.

Also targeted for closure by the Base Realignment and Closure Commission was Otis Air National Guard Base in Massachusetts, whose F-15 fighters were the first to reach New York on Sept. 11, 2001. The president and Congress can still reject the commission’s recommendations, but base supporters see little chance of that happening.

When the Pentagon first released its list of recommendations to the commission, it proposed moving all of Brunswick’s planes and changing its mission – but keeping the airfield open in case it was needed down the road.

In the weeks leading up to the commission’s Aug. 24 vote to close the base, Maine’s congressional delegation played up the national security concerns should the base be closed.

Two defense officials wrote letters to Maine political leaders reiterating their desire to see at least a scaled-back version of the base remain open. They said the base was an important part of the national defense capability for homeland security, aircraft refueling and as a logistics hub as well as providing “surge capacity” for the Navy.

The commission, however, defied the Pentagon and voted 7-2 to close the base altogether to give Maine officials an opportunity to redevelop the base.

The vote means that the closest active-duty military airfield to New England is now McGuire Air Force Base in central New Jersey, more than 400 miles from Brunswick. That base is home to a total of 61 KC-135, KC-10 and C-17 refueling and cargo aircraft.

During the debate on whether to close Brunswick, commissioner Harold Gehman Jr., a retired Navy admiral, said New England has other Air Guard and reserve bases that could be used to accommodate surveillance aircraft if needed in the future after the Brunswick base closes.

While there are plenty of airfields around New England for landing and fueling, Tetrev said they lack the security, the weapons, the magazines, the equipment and the personnel to make them effective staging areas if needed.

“The threat right now is terrorism, and the North Atlantic is the closest approach from Europe,” Tetrev said. “They’ve got to come through the North Atlantic, and the best way to stop that is to have a base in the Northeast.”

Around Brunswick, the drone of the P-3s flying overhead has long represented the sound of security. Louise Ansari, a town councilor, said people remember that two terrorists, including alleged mastermind Mohamed Atta, passed through Maine the morning of the Sept. 11 terrorist attacks.

“Seeing what’s happening around the world, in Iraq and in London, things like that get people nervous,” she said. “People are thinking, ‘What is the government thinking by closing the base?”‘