Navy Secretary Lehman: a well-versed, outspoken hard-liner

John Lehman, who took up his post last year at age 38, is one of the youngest Navy secretaries in US history. He also may be one of the most powerful.

Mr. Lehman holds office at a time when, following trouble in Iran and concern for the Persian Gulf and Caribbean region, the Navy is seen as increasingly important. He is part of an administration that not only wants to spend a lot more on defense, but also is decentralizing considerable Pentagon authority to the service secretaries.

Lehman has a masters degree from Cambridge University in Great Britain, and a doctorate in international relations from the University of Pennsylvania. He has served in the Pennsylvania National Guard and Air Force Reserve. He now is a commissioned officer in the US Naval Reserve, with the rank of commander. He is a trained naval flight officer, and has flown on active duty as a bombardier-navigator.

Lehman was on the National Security Council staff from 1969-1974 under Henry Kissinger. He was a US delegate to the mutual balanced force reduction talks in Vienna in 1974-75. He was then appointed deputy director of the US Arms Control and Disarmament Agency and served until 1977.

The Navy secretary is well-versed in military, diplomatic, and arms control affairs. His outspokenness and hard-line stance have made him controversial at times. He has not hesitated to openly criticize those defense contractors that in his view have tried to cheat the government.

In an article for Strategic Review last summer, he said:

* ''Nothing below clear (US) superiority will suffice. . . .''

* ''The endeavor will be made to identify and exploit Soviet weaknesses, such as inherently unfavorable maritime geography. . . .''

* ''For strength to be credible, it is absolutely vital that the world clearly perceive the determination by the United States to act and use strength when its interests are threatened.''