This two-part article recounts the 1968 phenomenon known as the Prague Spring and the U.S. SIGINT response during its demise. The Prague Spring was a short-lived attempt by a liberal Czechoslovakian communist government to ease the restrictions placed upon Czechoslovakian citizens by previous conservative communist governments. It was soon repressed by other member countries of the Warsaw Pact, which saw in the liberal movement a threat to their own regimes and to world communism. The first part reviews events leading up to the invasion of Czechoslovakia by its Warsaw Pact brethren. The second part details the reasons why [redacted text] the invasion was to begin. It examines the invasion — Operation Danube ’68 — and its aftermath, which will be discussed in a subsequent edition of the Cryptologic Almanac.

Alexander Dubcek

When Alexander Dubcek was elected first secretary of the Czechoslovak Communist Party (KSC) in January 1968, he intended to “put a human face on communism.” His government drafted an “Action Program” outlining its goals, which were basically, a return to socialism as it had existed in the country from 1945 to 1948, before the Soviet Union imposed a harsher regime of communism. He presided over a widespread popular movement to “de-Stalinize” and “democratize” communism in Czechoslovakia. The entire country was giddy with the spirit of reform. The world dubbed it the “Prague Spring.” But the forces of darkness — hard-liners in the KSC, the communist dictators of East Germany and Poland, and their masters in Moscow — watched with growing alarm, fearing the potential loss of control in their own countries and perhaps the untimely demise of the peasants’ and workers’ revolution. Shortly before midnight (GMT) on the night of 20 August 1968, Soviet and Warsaw Pact tanks rumbled over the Czechoslovakian borders, replacing the “Prague Spring” with a long winter’s night that was to last for 20 years.

Alexander Dubcek

Alexander Dubcek was an unlikely rebel. Born in 1921 at Uhrovec, Slovakia, he was the son of two dedicated communist parents, who had recently returned to Slovakia from Chicago. Dubcek joined the Communist Party in 1938 and fought against the Nazis in the Czechoslovak resistance during World War II. His communist pedigree was impeccable, and he rose rapidly through the Party’s ranks. By 1963 Dubcek was using the phrase which was to become associated with his administration and succinctly enunciated his reform goals: “Socialism with a human face.” Upon his selection as first secretary, he started by rehabilitating the victims of the 1948-55 communist purges.

Dubcek’s Reforms

Political debate became both possible and public. Radio, television, and newspapers jumped into the discussion of the country’s future. Travel became easier. Dubcek ended censorship – somewhat to his later chagrin. Once-silenced writers began to write again, and Ludvik Vaculik’s “The 2,000 Words,” an anti-authoritarian manifesto, condemned the Communist Party as a “power organization… attractive to egoists … to calculating cowards and to people with bad consciences.” Western influences — from jazz clubs to miniskirts –were felt, especially in Prague. Students danced in Prague’s Old Town Square.

With the coming of the Prague Spring, many staunchly pro-Soviet commanders in the Czechoslovak Army (CLA), Ministry of Defense personnel, and Secret Police (StB) were removed from their positions; those conservative officers who were allowed to remain on duty became increasingly isolated and lost their influence.

Soviet angst was brought to a higher level by a mid-July news conference, in which General Vaclav Prchlik, head of the KSC’s military department, roundly criticized the Soviet hegemony within the Warsaw Pact and condemned the Soviets and the Warsaw Pact’s other members who “arbitrarily stationed their troops on [Czechoslovakian] Territory.” Prchlik called for broad changes in the alliance and Czechoslovak policy, which might affect nuclear weapons deployment. Fanning the flames were reports reaching Moscow that a group of Czechoslovakian officers under Prchlik’s guidance were actually preparing plans to resist a Soviet-Warsaw pact invasion! That did it – Prchlik would have to go! An authoritative article in the main Soviet military newspaper Krasnaya Zvezda described Prchlik as “so blinded by ‘liberalization’ that [he] … is even prepared to debate publicly the most confidential state and military matters.” Marshal Ivan Yakubovskii, commander in chief of the Warsaw Pact Military Forces, and other Soviet leaders reiterated the, point in classified letters to Dubcek, charging that Prchlik had “revealed top secret provisions in interstate treaties” and demanding that Czechoslovakia “immediately live up to its allied obligations” to prevent further “disclosure of interstate secrets that bear on the security of the socialist countries.”

Soviet ire must have increased again when Prchlik was reassigned to other military duties rather than being fired in disgrace. His new position allowed him to continue working on the draft of the new national security Action Plan. In consequence, Soviet army commanders lost all faith in their Czechoslovakian counterparts long before the invasion.

Warsaw Pact Concerns

The expanding freedom in Czechoslovakia earned Dubcek the support of the majority of its citizens, but hard-liners in the KSC began to coalesce against him, especially Vasil Bil’ak, Alois Indra, and Drahomir Kolder, who feared his reforms. Leaders of other Warsaw Pact countries — East Germany’s Walter Ulbricht and Poland’s Wladyslaw Gomulka, as well as Todor Zhivkov of Bulgaria — were deeply concerned that the spirit of reform might spread to their countries. Indeed, Polish students had already rallied for change, and the slogan “Poland is waiting for its own Dubcek” had appeared on more than one wall. Ulbricht and Gomulka were among the first voices calling for military intervention. For the Russians’ part, they saw the Prague Spring as a threat to their hold .over Eastern Europe.

The major Soviet concern, however, was not political but military. According to recently available evidence, the Soviets believed that the lack of a permanent Soviet troop presence in Czechoslovakia was a serious impediment to Warsaw Pact military preparedness against NATO, and they had long pined to create a Soviet Group of Forces, Czechoslovakia (SGFC). Repeated requests, beginning in the 1950s and ’60s, had been turned down by even Dubcek’s hard-line predecessors. The Prague Spring would disrupt the Soviets’ plan for a “joint” nuclear weapons deployment plan which they had concluded with the Czechs in a secret agreement in the mid-1960s.

During the crisis, Marshal Yakubovskii several times urged the Czechoslovaks to accept a “temporary” deployment of Soviet troops in Czechoslovakia during the period of time when the crisis was still building. The requests, of course, were again refused. Some analysts believe that prior to the Prague Spring, the Soviet high command might have agreed, albeit reluctantly, to rely on Czechoslovak forces to provide the physical security for the three depots which were to be constructed in Western Bohemia, with KGB troops in tight control of the nuclear warheads. There was no reason to question the loyalty of the Czechoslovakian Peoples Army (CLA), which was considered to be the model component Of the Warsaw Pact forces. Further, there were Soviet “representatives” at all levels of the CLA. After Prchlik’s thoughts on the future role of the Czechoslovak military were published, Soviet military leadership lost confidence in their Czechoslovak colleagues, concluding that it was too risky to store nuclear warheads in Czechoslovakia unless the storage sites were converted into larger bases for Soviet forces. It appears, by the location and scale of the Soviet pre-invasion exercises, that they were intended in part to protect the three sites chosen as sites for the nuclear depots.

The KGB’s Involvement

Recent disclosures, according to journalist Mark Kramer, have borne out earlier assumptions that the KGB acquired undue influence during the 1968 crisis. Equally evident is the fact that, as revealed by former KGB and StB operatives in the mid-1970s, accurate information about events in Czechoslovakia in 1968 often was not sent on to the proper authorities in Moscow. Many of the assessments were deliberately alarming. What motivated these security services to withhold information or to report deliberately misleading information?

Soviet security service operatives believed that NATO was exploiting, or somehow would exploit, the situation in Czechoslovakia in 1968. The ferment caused problems for virtually every branch and department of the KGB. Soviet influence over Czechoslovakian security and intelligence had waned after early 1968, with the removal of StB officers friendly to Moscow, including General Josef Houska, Chief of the StB. The KGB’s First Main Directorate (foreign intelligence gathering branch) became even more concerned when Czechoslovak Interior Minister Josef Pavel disclosed that there were six KGB liaison agents assigned within his office; he implied that they would soon be removed. Later, he characterized the discovery of an arms cache in western Bohemia as a KGB provocation.

The Piller Commission had been set up to investigate the political trials of the 1950s. In July 1968 the Commission’s chief researcher, Karel Kaplan, began publishing a series of articles related to the Commission’s findings which left no doubt that the final report (not released before the invasion and suppressed afterwards) would show the Soviet Union in a very unfavorable light. Some KGB case officers may have feared that the report would lead to harsh reprisals against StB officers whose main loyalty had been to Moscow. The Piller Commission recommended the dissolution of the secret police, and the KSC had tentatively accepted that recommendation just before the Cierna nad Tisou conference. If carried out, this would eradicate the Soviet Union’s entire intelligence network in Czechoslovakia. Thus the perception within the KGB was that the Prague Spring constituted a threat to the internal and external security of the Soviet Union.

Initially, support for an invasion was by no means unanimous among senior KGB officers, especially those responsible for collection of foreign intelligence. Nonetheless, an increasing number of senior officers came to the conclusion that military intervention was necessary.  Once the seniors had decided that an invasion was called for, they began to manipulate, distort, and otherwise “manage” what senior political officials saw.

Concern over the situation in Prague led the Soviets to ‘convene, beginning in March 1968, a series of conferences on the situation in Czechoslovakia. The March conference was a meeting of the Warsaw Pact countries in Dresden, East Germany. Pointedly, the Czechs were not invited. They Were invited, however, to several other conferences – in Moscow (4 May), Moscow (14 July) – which the Czechs declined to attend – and Cierna nad Tisou (1 August), a highly unusual face-to-face meeting with Brezhnev and the Politburo. The multilateral conference at Bratislava (3 August) produced the “Declaration Of Bratislava.” The “Declaration” was a general statement of socialist principles which papered over the disagreements and preserved a modicum of public accord. For a while, it appeared that the two sides had reached consensus, the tension between the two was easing, and that there would be no need for Soviet intervention.

Internal Dissent

Shortly after the invasion, there was a joke floating around Prague –

Question: When will the Soviets leave Czechoslovakia?

Answer: When they find out who sent them the invitation.

Who did send the Soviets the invitation? There were quislings at work in Prague – two letters were sent to Soviet leader Leonid Brezhnev, inviting Soviet intervention. Both were written by Czechoslovakian Communist hard-liners in the KSC Presidium. On 14 and 15 August, Czech hard-liners met secretly with Stephan Chervonenko, the Soviet ambassador to Czechoslovakia. They advised Chervonenko that as soon as Soviet troops went into action, “healthy forces” of the KSC would set up a “provisional revolutionary government of workers and peasants.” Only a last-minute change of heart by two hard-line supporters to support Dubcek and oppose the invasion sounded the death knell for the hard-liners’ plans. They were unable to make good on any of their promises.

The Slippery Slope

On 3 May, an unauthorized demonstration in Old Town Square turned into an anticommunist rally. The Russians were quick to react.

When Dubcek and his principal lieutenants made a hurried trip to Moscow on 4 May 1968, it was showdown time over the Prague Spring reforms and the general direction that Czech communism was to take. The official communique described the meeting as engendering a “comradely atmosphere,” which author Tad Szulc describes as “Communist shorthand for cold disagreement.” While there was no invasion, Western analysts saw it as a stem warning. Dubcek ignored it.

[redacted text] By the end of the month, there were nine line divisions and three army headquarters positioned just north and east of Czechoslovakia.

On 24 Maya joint communique was issued announcing that Warsaw Pact exercises would take place in Poland and Czechoslovakia in June. The exercise, named Sumava, was held from 18 to 30 June. The scenario envisioned a three-pronged invasion of Czechoslovakia, with Czechoslovak forces representing NATO as the sole defender. Soviet, Polish, East German, and Hungarian forces portrayed the invaders. [redacted text]  This exercise was, in fact, a dress rehearsal for the actual invasion in August. At the conclusion of the exercise, Warsaw Pact forces did not return to their home stations, but remained in Czechoslovakia until mid-July.

On 23 July another large-scale exercise, to be held along the Czechoslovak border and in western Russia, Byelorussia, and Latvia was announced. The objective of this exercise was to work out rear services procedures. On 30 July the Soviets announced that the exercise, which did not include Czechoslovak troops, would be extended into Poland and East Germany.

A 10 August communique announced the beginning of a communications Exercise [redacted text] 

Source: NSA