In the fall of 1979, a furor erupted in the United States over the discovery of Soviet combat troops in Cuba. Scarcely remembered today, it was an episode of the Cold War that seemed like a very big deal at the time, so much so that it prompted U.S. president Jimmy Carter to address the American people on nationwide television.

Ultimately, it was an uproar over practically nothing, but it helped derail a major nuclear arms agreement between the United States and the Soviet Union and signaled that the era of détente between the two countries was coming to an end.

Cuba had been a bugaboo of U.S. policymakers since the communist revolution that put Fidel Castro in power in 1959. The widespread American fear that the USSR would use the island nation as a foothold from which to threaten the United States in its own hemisphere reached its high point in October 1962 during the Cuban Missile Crisis, but it didn’t end there.

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On Sept. 16, 1970, an American U-2 reconnaissance aircraft detected evidence that the Soviet Union was constructing a long-term naval facility at the Cuban port of Cienfuegos, one which could serve as a permanent base for Soviet ballistic missile submarines. U.S. officials in the Nixon administration raised objections with Moscow, stating that such a move would contravene the USSR’s commitment following the Cuban Missile Crisis to refrain from introducing offensive military forces into the Western Hemisphere.

The Soviets, who denied that they were building such a base, ultimately withdrew the submarine tender and two support barges it had sent to Cienfuegos and for the most part the matter died down.

Another, more minor controversy arose in November 1978 when it came to light that the Soviet Union had provided Cuba with between 12 and 24 MiG-23 fighter-bombers seven months earlier. These were tactical aircraft, not strategic bombers, but they were capable of carrying nuclear weapons.

However, U.S. intelligence quickly determined that the Cuban MiG-23s were not nuclear capable. Officials in the Carter administration assured the public that there was no evidence of Soviet nuclear weapons being present in Cuba and that the MiGs were too few in number to pose a military threat to the United States.

The 1979 crisis arose not because of any specific action taken by the Soviets or the Cubans, but because of a reexamination of existing information already held by the U.S. intelligence community. Concern had been mounting for some time in the United States about Soviet-Cuban support for pro-communist forces in Latin America. In March, National Security Advisor Zbigniew Brzezinski ordered Stansfield Turner, then Director of Central Intelligence, to undertake an overall assessment of Soviet forces present in Cuba.

The review, completed in July, determined that there was what appeared to be a brigade-size contingent of Soviet combat troops on the island, one that was separate from the Soviet training mission that the United States had long known was there.

It was unclear what the unit’s purpose was, but its presence represented a new and disconcerting discovery, one that was bound to create a stir in Washington. Rumors of the report’s findings began to surface in late summer, and the Carter administration decided at the end of August to begin informing key members of Congress.

What followed was a textbook example of a political crisis almost entirely devoid of substance. The presence of 2,000 to 3,000 Soviet combat troops in Cuba was unacceptable to many Washington leaders, both Republican and Democrat.

Sen. Frank Church, a liberal Democrat from Idaho who served as the chairman of the Senate Foreign Relations Committee, immediately demanded the brigade’s removal. “The United States,” he said on Sept. 4, “cannot permit the Soviets to establish a military base on Cuban soil, nor can we allow Cuba to be used as a springboard for real or threatened Russian military intervention in the hemisphere.”

Sen. Richard Stone of Florida echoed this sentiment, arguing that the brigade’s deployment violated the Monroe Doctrine. Howard Baker, the Republican leader in the Senate, stated that if the U.S. tolerated the presence of Soviet combat troops in Cuba, “we will in effect be letting the Soviet Union thumb their noses at us.”

Ronald Reagan, preparing for his run for the presidency in 1980, said that the United States “should not have any further communications with the Soviet Union” until the troops were withdrawn.

When the news broke, the Carter administration scrambled to get ahead of the issue. It faced the difficult task of persuading Congress and the general public that it was taking the situation seriously without further fanning the flames of alarm. On Sept. 5, Secretary of State Cyrus Vance told reporters that “the presence of this unit runs counter to long‐held American policies.”

Two days later, the president called a news conference and stated that “this status quo is not acceptable.”

But the newly discovered Soviet troops were not new at all. According to U.S. intelligence, they had been present in Cuba since at least 1976, and possibly much longer than that. Moreover, it was widely understood at the time – even by those who voiced the most alarm at the discovery – that the small Russian force posed no military threat to the United States.

It consisted of a headquarters unit, a tank battalion and three motorized rifle battalions, but it had no air- or sea-lift capability and there were no indications that it was equipped with nuclear weapons. So why was its discovery in Cuba so distressing to U.S. political leaders?

The uproar over the Soviet brigade arose at a pivotal time. The preceding decade had witnessed a substantial thaw in relations between the United States and the USSR, a period commonly known as détente. By the end of the 1960s, both superpowers were ready to move away from the tensions that had characterized the first 20 years or so of the Cold War, a time when it often seemed that war could break out at any moment.

The United States was bogged down in a difficult and unpopular war in Vietnam while the Soviet Union found itself facing a major new threat from China following the Sino-Soviet split. Moscow and Washington both recognized that while the two nations were not friends, they could work together in some areas to mutual advantage.

One of those areas was arms control. In 1969, the two superpowers began strategic arms limitations talks, or SALT, to curb the ongoing nuclear arms race. Three years later, they reached an agreement that froze the number of ICBMs and SLBMs that each side could possess. The SALT I accord was an interim arrangement intended to set the stage for a new round of negotiations known as SALT II.

It did not place any limits on the number of warheads the two nations could deploy on their missiles, nor did it impose any constraints on the size of either nation’s conventional military. It was, however, hailed as an important step forward in improved U.S.-Soviet relations.

There were other aspects of détente, too. The two nations agreed to limit their ballistic missile defenses and spearheaded the signing of a global agreement to cease production of biological weapons. Trade between the U.S. and Soviet Union increased, as did scientific and cultural exchanges. To many observers in the 1970s, the improvement in U.S.-Soviet relations seemed permanent. Indeed, it was common at the time for people to refer to the Cold War in the past tense.

In retrospect, however, it is clear that détente represented only a temporary lull in the Cold War, not the end of it. The United States and the Soviet Union remained geopolitical and ideological rivals, even if the intensity of their competition appeared to have lessened.

From the American perspective, there were two main reasons why détente began unraveling in the second half of the decade. One was the ongoing Soviet military buildup. Soviet conventional forces expanded throughout the 1970s while the American military contracted as part of the post-Vietnam drawdown. Soviet forces in Eastern Europe underwent a significant modernization effort over the course of the decade and added around 150,000 men.

The Soviet navy, previously only capable of coastal defense, grew from 215 ships to 279 while American naval forces shrank by nearly a third.

Even more worrisome was the growth of the Soviet strategic nuclear arsenal. The United States had enjoyed a decisive lead in nuclear weapons since the beginning of the arms race, but the Soviets sought to close the gap following the Cuban Missile Crisis. During the 1970s, the Soviets began augmenting their nuclear forces by adding multiple independently targetable reentry vehicles to their existing launch platforms, something the United States had already begun doing a few years earlier.

Most of the increase in the USSR’s arsenal occurred in its ICBMs, which were becoming accurate enough to destroy U.S. missiles in their underground silos. A 1977 study by the Congressional Research Service forecast that by the end of the decade the USSR would possess nearly 4,600 nuclear warheads on its fleet of ICBMs, more than twice the U.S. number.

The second reason for détente’s collapse was the resurgence of hardline anti-Soviet sentiment as a political force in the United States. Strident anti-communism among U.S. political and military leaders dated back to the beginning of the Cold War and was embodied by individuals such as Arizona senator and 1964 GOP presidential candidate Barry Goldwater, a man who once called for the United States to completely withdraw diplomatic recognition of the USSR.

But conservative hawks, crippled by Goldwater’s defeat and, even more significantly, by the disastrous war in Vietnam, found themselves exiled from mainstream American politics for a time. By the second half of the 1970s, however, disillusionment with détente and concerns about the Soviet buildup facilitated the emergence of a new, post-Vietnam strain of right wing foreign policy beliefs.

The hawks viewed the Soviet Union in explicitly Manichean terms. The USSR’s goal, in their minds, was nothing short of global conquest. It was not a normal nation-state led by rational leaders, they claimed, but a moral evil that the United States had to confront anywhere and everywhere in order to protect itself and other free nations from destruction. They saw détente as a carefully planned effort by Moscow to lull U.S. leaders into complacency while the USSR grew more and more powerful.

One of the most prominent hawks was Richard Pipes, a professor of Russian history at Harvard University. In 1976, Pipes led a team of anti-détente conservatives commissioned by the president’s Foreign Intelligence Advisory Board to critique the CIA’s assessments of the Soviet Union.

Unsurprisingly, this group, which became informally known as “Team B,” produced a report that charged that the American intelligence community was gravely underestimating both the size of the Soviet buildup and the scope of its ambitions. It concluded that “all the evidence points to an undeviating Soviet commitment to what is euphemistically called ‘the worldwide triumph of socialism’ but in fact connotes global Soviet hegemony.”

Team B’s assessment was released to the public shortly after it was completed, and its contents ended up serving as a blueprint for détente’s growing number of critics who argued that the U.S. was destined to lose the Cold War if it did not adopt a more adversarial approach to the Soviet Union. They pointed to the Soviet buildup and the USSR’s increasing involvement in Third World countries such as Angola, Yemen and Ethiopia as evidence of its expansionism.

In truth, the alarmism of the right overlooked a number of important facts. It was true that the Soviets were strengthening their military, but this effort appeared to be a response to the U.S. buildup of a decade earlier. Moreover, one quarter of Soviet ground and air power was deployed opposite China rather than the West. U.S. intelligence indicated that morale was poor among Soviet troops and that the Red Army was struggling to address widespread drunkenness among its soldiers.

By the late 1970s it was also clear that the Soviet economy, already vastly smaller than that of the United States, was in a state of long-term decline, as was the size of its labor force.

There was more. Total defense spending by the NATO alliance exceeded that of the Warsaw Pact nations, many of which Moscow considered politically and militarily unreliable. While Soviet strategic nuclear forces were growing more powerful, they remained numerically and technologically inferior to those of the United States, most of which were carried by invulnerable ballistic missile submarines. The United States had also begun to develop an array of new, advanced weapons such as the MX missile, the M-1 tank and precision-guided munitions whose sophistication the Soviets could not match.

Nevertheless, these two factors, the Soviet buildup and the reemergence of anti-Soviet hardliners, had the effect of shifting the U.S. foreign policy debate significantly to the right. By the second half of the 1970s, the hawks had all but taken control of the Republican party, at least in terms of its approach to international affairs. However, many moderate and conservative Democrats were also calling for greater U.S. military spending and a tougher stance toward the USSR.

Politically, the hawks directed their anger at the Carter administration, even though the détente policies they loathed had begun under Pres. Richard Nixon. After taking office in January 1977, Carter quickly developed a reputation as an indecisive leader whose foreign policy was disjointed at best. He had greatly upset conservatives by persuading the Senate to ratify a treaty turning control of the Panama Canal over to the Panamanian government and then canceling production of both the neutron bomb and the new B-1 strategic bomber.

In May 1978, all 38 members of the Senate Republican caucus released a public statement that criticized Carter for “compromising America’s ability to defend itself.”

“In 15 short months of incoherence, inconsistency and ineptitude, our foreign policy and national security objectives are confused and we are being challenged around the globe by Soviet arrogance,” it read.

Eight months later, a group of national Republican leaders issued a subsequent statement that argued that “the Carter administration is responsible for and presiding over the decay of American influence and the decline of American military power.”

Polls indicated that these attacks were having an impact on popular opinion. A New York Times/CBS News survey in June 1979 found that 43 percent of respondents agreed with the assertion that the United States was “not as strong” as the USSR. Thirty percent were of the view that the two superpowers were equally powerful while only 11 percent said that the United States was stronger.

In terms of policy, the hawks’ primary objective was the defeat of the SALT II treaty. Efforts to negotiate a follow-on agreement to SALT I had been underway for years, and details of the new accord were finalized in the spring of 1979. The agreement was long and complicated, but its most important provision was to limit the United States and USSR each to a total of 2,250 nuclear delivery vehicles – ICBMs, SLBMs and strategic bombers.

Those on the right expressed opposition to the treaty even before negotiations were completed. Some opponents of SALT II voiced specific criticisms of the agreement, such as its failure to limit the size of the Soviet fleet of medium-range Backfire bombers. For the most part, however, hawks opposed it because they saw it as a form of appeasement, with some explicitly comparing it to Neville Chamberlain’s 1938 Munich agreement with Hitler.

Two months before it was finalized, a group of retired military officers released a 62-page report denouncing SALT II as an “act of phased surrender” to the Soviet Union. In their view, the most important reason for rejecting the agreement was that it served as “a symbol of defeatist policies which have led to phased surrender by the United States as it retreats around the world in the face of Soviet aggression.”

It was against this backdrop that the 1979 imbroglio over the Soviet brigade in Cuba took place. When its presence was made public, conservatives pounced. They argued that the USSR’s decision to deploy troops so close to American shores was further evidence, if any was needed, of the Soviet Union’s aggressive intentions.

Sen. Henry “Scoop” Jackson, a Democrat from Washington state and one of the nation’s most outspoken hawks, charged that the brigade’s deployment to Cuba “is not an isolated event.” Rather, it represented “a most dramatic example of a pattern of Soviet and Cuban behavior which is hostile to the interests of the United States, its friends and allies.”

Conservatives also blamed the situation on Carter’s weak leadership, even though the evidence indicated that the brigade was already there when he took office. “There is no doubt in my mind [that] this administration and its policies have been instrumental in placing us in the situation we find ourselves today,” Republican senator Strom Thurmond said.

Many unfavorably compared Carter to Pres. John F. Kennedy, who had — in the popular narrative — stood firm against Nikita Khrushchev during the 1962 Cuban Missile Crisis and forced the Soviet Union to remove its missiles.

Yet the two situations were hardly analogous. Even the most strident anti-Soviet hardliners acknowledged that the relatively small number of Red Army troops in Cuba posed no military threat to the United States. It was also true that the U.S. maintained a force 4,700 troops in Turkey, a nation that bordered the USSR, as well as 2,200 American military personnel at the Guantanamo Bay naval base located in Cuba itself.

From the beginning, the brigade controversy became linked to the Senate’s consideration of SALT II, despite the Carter administration’s protestations that the two matters were unrelated. Church, the chairman of the Senate’s Foreign Relations Committee, stated a few days after the brigade’s discovery was announced that there was “no likelihood whatever” that the Senate would ratify SALT II until the unit was removed.

Sen. Russell Long, a key moderate Democrat from Louisiana, announced a few days later that he would vote against ratification, citing the Soviet troops in Cuba as evidence that the USSR was acting in bad faith. A number of senators who were undecided about SALT II indicated that it would be hard for them to support the treaty unless the Cuba issue was satisfactorily resolved.

Through September, concerns about the Soviet troop presence in Cuba among members of Congress and the general public grew increasingly pronounced. U.S. Secretary of State Cyrus Vance met five times with Soviet ambassador Anatoly F. Dobrynin and twice with Soviet Foreign Minister Andrei Gromyko in an effort to persuade the Soviets to withdraw the troops, but Moscow made it clear that it was unwilling to do so, insisting that the brigade was there only to train Cuban military personnel.

The Soviet refusal left the White House in a political bind, since Carter had publicly stated that “this status quo is not acceptable.” Dogged throughout his presidency by criticisms that he was an unsteady leader who lacked the backbone to stand up to the Soviets, Carter faced enormous pressure to act firmly in order to shore up support for SALT II. At the same time, the president understood that there was nothing he could do to force the Soviets to remove the brigade without causing U.S.-Soviet relations to deteriorate further – a development that also would have undermined support for the treaty in the Senate.

On Oct. 1, Carter spoke to the American people about the situation in a nationally televised address. Seeking to walk a fine line between appearing too concerned and too unconcerned, he told the public that while the Soviet unit “presents no direct threat to us,” its presence in Cuba was nonetheless “a serious matter.”

He listed a number of steps the United States would take in response. These included the resumption of aerial surveillance flights over Cuba, the creation of a joint military task force responsible for the Caribbean, increased U.S. military exercises in the region, and expanded U.S. economic assistance to impoverished countries in Central America.

Carter also told the nation that Soviet officials had made “certain statements” to their American counterparts that the U.S. interpreted to mean that “they do not intend to enlarge the unit or to give it additional capabilities.” This was the closest thing that Carter could point to as a concession by Moscow.

None of the actions announced by Carter were particularly substantive – but, then again, neither was the supposed crisis they were intended to resolve. The president’s speech did little to change many minds about SALT II or U.S.-USSR relations generally, but the controversy began to slowly fade from view in the weeks following his address.

Political conditions in the U.S. in the fall of 1979 were such that the discovery of the brigade in Cuba was bound to set off a firestorm. Anti-Soviet hardliners who saw the USSR as an imminent, existential threat had succeeded in pushing American public opinion on foreign policy further and further to the right over the preceding years.

News of the Soviet forces in Cuba reached the public just a few weeks after Carter had submitted SALT II to the Senate for ratification. That the controversy unfolded shortly before the onset of the 1980 presidential campaign only added to the situation’s combustibility. Had the Soviet troops been detected a year or two earlier, it’s unlikely that it would have caused the furor that it did.

In the end, SALT II was never got a vote. The brigade issue delayed Senate action on the agreement until late 1979, by which time its fate was overtaken by events. The Soviets invaded Afghanistan at the end of December, and in response Carter officially asked the Senate to postpone its consideration of the treaty indefinitely.

His administration had planned to mount a renewed push for ratification at the start of his second term, but he lost his 1980 bid for reelection to Ronald Reagan, the favorite son of anti-Soviet hardliners and an expressed opponent of the treaty. Had the Soviet troops controversy not arisen, it is quite possible that SALT II would have been approved.

The uproar in the United States over the troops in Cuba was a strong indication that the era of détente was over. In his speech to the nation, Carter stated that “the brigade issue is certainly no reason for a return to the Cold War.” But it had never really ended, just diminished in intensity.

The improvements in superpower relations during the 1970s were real, but they were not enduring. Although it is little remembered today, this controversy in 1979 served as an unfortunate prelude to the dangerous tensions that existed between the United States and USSR in the early 1980s, a period during which the risk of nuclear war was as high as at any other moment in the Cold War.