Defense Secretary Harold Brown has just sent the service chiefs a secret master plan directing them to structure their forces to stop a Soviet blitzkrieg in Europe and put out a brush fire war in a place like the Persian Gulf.

Brown's guidence for the five-year period 1980 through 1984 shows a heavy European orientation but warns the chiefs that conflicts in the Persian Gulf "could soften the glue" of the NATO alliance "as surely" as Soviet superiority along the NATO front.

He orders the services to reshape their forces in a number of ways, including forming a quick-strike team of Army and Marine divisions for responding to sudden conflicts.

A fireman role for the Marines would mark their most significant mission in Europe since World War I. The planned shift underscores the Carter administration's emphasis on the Atlantic rather than tha Pacific theater.

Brown's guidance document some of which were obtained by the The Washington Post, disclose these other directions in military policy:

The Army is to proceed with its plans to deploy in Europe improved nuclear warheads - presumably the enhanced radiation warhead called the neutron bomb - and to develop a longer-range Pershing missile.

The Air Force is directed to modify its newest B52H bombers for the dual role of either firing cruise missiles or having the capability to penetrate enemy defenses to drop nuclear bombs.

The Navy is build three Trident missile carrying submarines every two years and start putting Polaris submarines in mothballs soon, called "caretaker status."

In justifying an all-service effort to strengthen NATO firces, Brown told military leaders, "We face an immensely strong and growing military power to the East.

Our near-team objective is to assure that NATO could not be over-whelmed in the first few weeks of a blitzkrieg war, and we will invest and spend our resources preferentially to that end.

"When that assurance is reasonably in hand," Brown continued in a "consolidated guidance" overview document, "we will turn our attention to wqat additional capability, if any, NATO might need to be able to fight for at least as long as the Warsaw Pact."

However, Brown continued, "events in the Persian Gulf could soften the glue that binds the alliance as surely as could an imbalance of military force across the inter-German border. But we are as yet unsure of the utility of U.S. military power in Persian Gulf contingencies" and are studying the question.

A Soviet thrust against to NATO, Brown's guidance indicates, would constitute a full war and a flareup in the Persian Gulf a half war. He directed the service to prepare to fight 1 1/2 wars at once.

To fight a "half war," Brown ordered a new outfit to be organized, constituted of a division of Marines, with its air wing, plus two reinforced Army divisions.

It "should be structured, manned and equipped for contingencies that could precede a major war in Europe," Brown said of this quick-strike force.

Warning the services that future Pentagon budgets will be increased only modestly, he said military leaders should keep only enough rear echelon forces to support simultaneously 30 days of war along the NATO front and a half-war elsewhere of indefinite duration.

In discussing battlefield nuclear weapons for NATO, Brown told the services to stop developing or deploying new underground nuclear mines or nuclear-tipped anti-aircraft missiles.

Instead, he said, they, should proceed with plans to put improved nuclear shells in the 155-mm and 8-inch artillery batteries in Europe and on the Lance tactical missile. Lance has a range of about 56 miles. President Carter has said the neutron warheads for these weapons will not be deployed unless the NATO allies want them. Brown's guidance appears to assume such approval will be forthcoming, although there is time to call off deployment.

In designing new nuclear weapons for the battlefield, Brown wrote, the emphasis should be on destroying mobile targets such as tank formations "with less collateral damage" than that inflicted by present-day nuclear weapons. The neutron warhead is designed to kill tank crews with radiation without blasting away as much of the surrounding countryside as conventional nuclear weapons.

Research on the "earth penetrator" nuclear warhead for the Preshing II missile under development "should be continued," Brown said. The earth penetrator would be designed to bury itself in the ground before exploding in a mountain pass like a atomic mine.