The Green Berets, glamorized by John Wayne during the Vietnam war and de-emphasized by Army brass since then, are making a comeback.

The Reagan administration has decided to give them a larger role in the military bureaucracy and on the world stage, Brig. Gen. Joseph C. Lutz said at a meeting with reporters at the Pentagon yesterday.

The first step will be to tighten coordination of the scattered Special Forces Groups by putting them all under a new command at Fort Bragg, N.C., on Oct. 1.

Lutz will head this Special Operations Command.

Next will be a significant but slow growth of the Green Beret Force from today's 3,600 to 5,000 or so.

The ranks of the Green Berets swelled to 13,000 during the Vietnam war, offending many Army leaders who thought the elitism of the berets caused dissension.

"In many respects," said Lutz, "we were our own worst enemy" in the glory days of the Green Berets.

President Kennedy glamorized special forces and counter-insurgency in the early days of the Vietnam War, and John Wayne starred in a movie on the Green Berets.

As the war widened, Lutz said, the Green Berets often resented the movement of regular Army units into their areas of operation, and this poisoned relationships between Special Forces and regular Army leaders.

Since then, the Army high command has pared the Special Forces, while Green Beret leaders, for their part, have attempted to close the gap with regular units by playing down the macho, elitist image created during Vietnam.

"We're making a comeback," Lutz said.

Defense Secretary Caspar W. Weinberger paved the way for the Green Berets' comeback by stating in his secret defense guidance for fiscal 1984 to 1988 that they can "respond to contingencies of a nature which would render inappropriate the employment of regularly military forces."

His guidance included orders to have Special Forces ready "to exploit political, economic and military weaknesses within the Soviet bloc" and said "other opportunities for counter-offensives against Soviet interests, forces and proxy forces worldwide will be exploited to the extent possible."

Lutz said Special Forces, whose specialities range from highly secret operations to the open training of soldiers in emerging nations, will be useful in Africa, Latin America and Southwest Asia in the future.