When a local Marine Reserve unit full of lawyers and federal employees gets called to active duty in the Persian Gulf, you can bet they'll be doing what Washington does best: setting up a bureaucracy.

And although no one will say so publicly, military security being what it is, the fact that the 156-member 4th Civil Affairs Group, based at the Armed Forces Training Center in Anacostia, is needed over there makes it sound like the United States may be thinking about invading someplace like Kuwait.

After American troops occupy a place, the 4th Civil Affairs Group's mission is to rebuild the country's roads and bridges and the rest of the infrastructure, keep the utilities working, find food and shelter for civilians, help a new local government organize and set up a legal system -- thus all the lawyers.

"Our mission is more on the helping end of it, as opposed to the destructive end," said Capt. Doug Walker, a team commander in the unit.

This is the first time the entire unit has been activated, members said, and a Marine Corps source said that underscores the seriousness of the Middle East situation. The Marines' other civil affairs group, the 3rd, based in Los Angeles, was activated Dec. 4 for Desert Shield duty.

"It lets me know we mean business," the source said. "A civil affairs group normally does not come in until after the conflict takes place."

The last time some members of the 4th Civil Affairs Group were activated was after U.S. troops went into Panama to oust Manuel Noriega.

Col. Jim Leslie, an executive officer of the group, said what will happen in the Persian Gulf is "anybody's guess. It could be once we get over there, there could be no military action. We could get called back without a shot, or it could be World War III or anything in between."

Among those in the unit are Capt. Alford J. Lechner, a federal judge in New Jersey; Lt. Col. Jim Zumwalt, a lawyer and the son of retired Adm. Elmo R. Zumwalt Jr., former chief of naval operations; Lt. Col. Sam Routson, former deputy assistant secretary of the Navy; and Capt. Ernie Garcia, former sergeant at arms of the U.S. Senate.

The unit reported for duty Nov. 24. Its members left Washington for Camp Lejeune, N.C., where Marine reservists from across the country are processed. There, the unit was slated for training that includes marksmanship, engineering techniques and survival in the Middle East (watch out for snakes, drink lots of water), said Capt. Scott Campbell. The Marine Corps would not disclose when the unit will leave Camp Lejeune for Saudi Arabia.

Leslie said his two biggest fears are chemical weapons and terrorists. "It's similar to Vietnam, where you have a front line but have to be wary of terrorists that can be everywhere," he said. "No matter where you are, you are in a fair amount of danger. We're going to have a real tough time telling the good guys from the bad guys."

Civil affairs units also have a job to do in combat zones before the infantry arrives: try to prepare so that civilian casualties will be as low as possible.

They announce coming strikes to the local population using television, radio or public address systems. Sometimes, the units fly planes above combat zones, dropping leaflets telling civilians to clear out and spreading pro-American propaganda. And they are supposed to locate "temples of adoration," such as churches, to save them from the path of destruction.

"Our mission is to keep civilians from interfering with tactical operations. We keep the civilians from being injured," Leslie said.

For that job, the Marines have acquired what would be some pretty high-priced talent in civilian life. "It's a story of successful lives disrupted," said Gen. J.T. "Mike" Coyne, a former commander of the unit.

The current commanding officer of the unit, John Easton, is one of Coyne's law partners in the D.C. firm of Jordan, Coyne, Savits & Lopata. Two other officers in the unit are also lawyers in the firm.

Leslie, a real estate broker in Fairfax, said he was talking on the telephone trying to sell a house when he received the call to duty.

"I said, 'Would you hold please?' It was Colonel Easton saying we've been activated. Get my bags packed," said Leslie. "I left my desk like I would be coming back in another week. I left messages on my desk that may sit there for a year or two or three. People are still waiting for those calls."