Harold Brown (September 19, 1927 – January 4, 2019) was an American nuclear physicist who served as United States Secretary of Defense from 1977 to 1981, under President Jimmy Carter.

Previously, in the John F. Kennedy and Lyndon B. Johnson administrations, he held the posts of Director of Defense Research and Engineering (1961–1965) and United States Secretary of the Air Force (1965–1969).

[3] As Secretary of Defense, he set the groundwork for the Camp David Accords, took part in strategic arms negotiations with the Soviet Union, and supported, unsuccessfully, ratification of the SALT II treaty.

[4] At Livermore, Brown led a team of six other physicists, all older than he was, who used some of the first computers, along with mathematics and engineering, to reduce the size of thermonuclear warheads for strategic military use.

Brown and his team helped make Livermore's reputation by designing nuclear warheads small and light enough to be placed on the Navy's nuclear-powered ballistic missile submarines (SSBNs).

Consistent with the Carter administration's objective to reorganize the federal government, Brown launched a comprehensive review of defense organization that eventually brought significant change.

"[2] His later writings in his 2012 memoir, Star-Spangled Security, reinforced this agenda:[7]When I became secretary of defense in 1977, the military services, most of all the army, were disrupted badly by the Vietnam War.

There was general agreement that the Soviet Union outclassed the West in conventional military capability, especially in ground forces in Europe.According to The New York Times, experts say in retrospect that contrary to a popular narrative which asserts that President Ronald Reagan increased defense spending to ramp up competition with (and ultimately bankrupting) the Soviet Union,[4] it was Carter and Brown who began "maintaining the strategic balance, countering Soviet aircraft and ballistic innovations by improving land-based ICBMs, by upgrading B-52 strategic bombers with low-flying cruise missiles and by deploying far more submarine-launched missiles tipped with MIRVs, or multiple warheads that split into independent trajectories to hit many targets".

[4] Brown considered it essential to maintain the triad of ICBMs, SLBMs, and strategic bombers; some of the administration's most important decisions on weapon systems reflected this commitment.

Although he decided not to produce the B-1 bomber, he did recommend upgrading existing B-52s and equipping them with air-launched cruise missiles, and gave the go-ahead for development of a "stealth" technology, fostered by William J. Perry, under-secretary of defense for research and engineering, that would make it possible to produce planes (bombers as well as other aircraft) with very low radar profiles, presumably able to elude enemy defenses and deliver weapons on targets.

[2][4] By early 1979, Brown and his staff had developed a "countervailing strategy", an approach to nuclear targeting that past secretaries of defense Robert McNamara and James R. Schlesinger had both earlier found attractive, but never formally codified.

The heart of PD 59, as Brown described it, was as follows:[2] It is our policy-and we have increasingly the means and the detailed plans to carry out this policy-to ensure that the Soviet leadership knows that if they chose some intermediate level of aggression, we could, by selective, large (but still less than maximum) nuclear attacks, exact an unacceptably high price in the things the Soviet leaders appear to value most—political and military control, military force both nuclear and conventional, and the industrial capability to sustain a war.

And, of course, we have, and we will keep, a survivable and enduring capability to attack the full range of targets, including the Soviet economic base, if that is the appropriate response to a Soviet strike.Because the almost simultaneous disclosures of PD 59 and the stealth technology came in the midst of the 1980 United States presidential election campaign; some critics asserted that the Carter administration leaked them to counter charges of weakness and boost its re-election chances.

In May 1978 the NATO heads of government endorsed a long term defense program which included 10 priority categories: enhanced readiness; rapid reinforcement; stronger European reserve forces; improvements in maritime capabilities; integrated air defenses; effective command, control, and communications; electronic warfare; rationalized procedures for armaments collaboration; logistics co-ordination and increased war reserves; and theater nuclear modernization.

He repeatedly urged the Japanese government to increase its defense budget so that it could shoulder a larger share of the Western allies' Pacific security burden.

Although the Carter administration decided in 1977 on a phased withdrawal of United States ground forces from South Korea, it pledged to continue military and other assistance to that country.

A year later Brown visited the PRC, talked with its political and military leaders, and helped lay the groundwork for limited collaboration on security issues.

He staunchly supported the June 1979 SALT II treaty between the United States and the Soviet Union and was the administration's leading spokesman in urging the Senate to approve it.

Partly to placate Senate opponents of the treaty, the Carter administration agreed in the fall of 1979 to support higher increases in the defense budget.

[2] In Middle East affairs, Brown supported President Carter's efforts as an intermediary in the Egyptian-Israeli negotiations leading to the Camp David Accords of September 1978 and the signing by the two nations of a peace treaty in March 1979.

[2][4] Elsewhere, the fall of the Shah from power in Iran in January 1979 eliminated a major U.S. ally and triggered a chain of events that played havoc with American policy in the region.

[2][4] The Soviet invasion of Afghanistan in December 1979 to bolster a pro-Soviet Communist government further complicated the role of the United States in the Middle East and Southwest Asia.

Brown explained that the RDJTF was responsible for developing plans for contingency operations, particularly in Southwest Asia, and maintaining adequate capabilities and readiness for such missions.

Subsequent budgets under Brown moved generally upward, reflecting high prevailing rates of inflation, the need to strengthen and modernize conventional forces neglected somewhat since the end of the Vietnam War, and serious challenges in the Middle East, Iran, Afghanistan, and elsewhere.