Nearly 70,000 people belonging to military reserves or National Guard units in the Washington area are eligible to be called up for active duty under the executive order signed yesterday by President Bush.

Reservists in key support positions, including nurses and doctors, mechanics and cargo handlers, will likely be the first to hear the telephone ring, called in to bolster domestic military operations that have been drained by the huge deployment to the Middle East.

Pentagon officials would not discuss what units will be activated; however, only a fraction of the 69,974 reservists or guard members in Virginia, Maryland and the District are likely to be called. Bush has the authority to summon 200,000 reservists, but administration officials have said the initial call will likely go to about 40,000 across the country.

Doctors, nurses and medical technicians are considered critically needed at Bethesda Naval Hospital, and cargo handlers and other support personnel are in demand at Norfolk Naval Base. Also high on the Pentagon's priority list are maintenance, water purification, shipping support and transportation units.

"Put it this way: We're in the thick of it," said Capt. David Branham, a reservist and spokesman for the 459th Military Airlift Wing based at Andrews Air Force Base. "I'm sure all of us will get a good night of sleep tonight, because who knows what'll happen tomorrow."

Including Army, Navy, Air Force, Marine and Coast Guard reserves as well as the Army and Air National Guards, there are 32,612 reservists subject to be called up in Virginia, 25,854 in Maryland and 11,508 in the District.

Among the major reserve units in the Washington area are the 459th Military Airlift Wing at Andrews, the 97th Army Reserve Command at Fort Meade and the 310th Theater Area Command at Fort Belvoir.

One of the first places reservists may be used locally is Bethesda Naval Hospital, where half of the 1,800-person active-duty medical staff has shipped out to serve aboard the USNS Comfort hospital ship in the Middle East. The depleted Bethesda hospital has been forced to cut its patient population in half, suspend almost all elective surgery and curtail other services.

"Our patients have come in saying, 'I'm sorry I came in,' " said Lt. Cmdr. William W. Clyde, a spokesman for the hospital. "The people need medical care and they're apologizing to us."

Although most of the reservists are expected to replace departed units in the United States, a few local units could be sent to the Middle East. Four minesweepers preparing to leave Little Creek Amphibious Base in Norfolk will be partly staffed by reservists, sources said, and, if activated, the flying unit of the 459th Military Airlift would go.

Local reservists, who knew little more than what they saw on the news yesterday, said they are ready to go if needed.

"When a president calls us, you have to go," said Greg Tsimbidis, a reserve marksmanship trainer assigned to the 310th Theater Area Command at Fort Belvoir in Fairfax County. "I hope there could be a peaceful resolution, but if he calls us, that's what they pay us to do."

Tsimbidis, who lives in Annandale and was advised not to leave town, said he wasn't worried about the possible effect a months-long deployment would have on his civilian job at a Chantilly cabinetry company. "I'd rather mess up my job than mess up my country," he said.