In the first installment of this article, we examined the circumstances leading up to the invasion of the newly liberalized Czechoslovakia. In this part, we will discuss the U.S. SIGINT response to the crisis, the invasion itself, and its aftermath

The SIGINT Story

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10 August Warsaw Pact forces communique announced the beginning of a communications exercise [redacted text]

David McManis, deputy chief of the Situation Room, was an NSAer and was keeping his eye on the developing events. He had established a good rapport with national security advisor Walt Rostow, and together the two were convinced that an invasion was imminent. But, like others, they felt they did not have enough information to predict the date.

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Operation Danube ’68 – the Invasion

At about midnight on 20 August, fifteen to sixteen Soviet divisions, augmented by three Polish divisions and smaller elements of Hungarian, Bulgarian, and East German forces left their assembly areas and entered Czechoslovakia. They struck from three directions: the largest concentration attacked from the north, along the East German border, headed for Prague and Pilzen, while smaller formations displaced from the Soviet Union’s Carpathian Military District, and from Hungary. At the same time, airborne forces departed bases in the Soviet Union, heading for key locations in Czechoslovakia. The Soviet blitzkrieg was not resisted by Czech forces, following the Czech Presidium’s appeal not to offer resistance.

The HQ of Radio Prague was, naturally, one of the invaders’ first targets. Twenty people were killed in the fight to control the radio station. With Dubcek and his top lieutenants arrested and hustled off to Moscow, Czechoslovak radio continued to broadcast. Ironically, the Soviets had aided the Czechs in constructing an underground radio broadcast system, for use in the case of enemy attack. Now it was used against them announcers, broadcasting from secret locations advised citizens to avoid violence. Instead, they were instructed to engage the soldiers in conversation, to write signs in Cyrillic telling them to go home, to hold out transistor radios to them while announcers told them in. Russian to go home. Warnings were issued to particular citizens “not to go home,” if they were in danger of being arrested. Messages were passed from one person to another, and citizens were asked to remove all highway signs, street signs, and house numbers in an effort to confuse the invaders. Essayist Lea Sevcik points out that this effort was so successful that the only signs remaining in the country were “those pointing to Moscow.”

What casualties resulted from the invasion? Kramer, citing a formerly classified

Czechoslovakian Ministry of the Interior document from late 1968, reports that “82

Czechoslovak citizens were killed, 300 were severely wounded, and 500 suffered minor wounds … between 21 and 28 September 1968.” From 29 September through 18 October, 18 more Czechs were killed and another 35 were wounded by the occupying forces. Total: 100 civilian deaths and 335 severely wounded. According to the report, the 435 citizens who were killed or severely wounded were not “using firearms of their own against the foreign soldiers.” As for the Warsaw Pact forces, only one death – that of a Bulgarian came at the hands of a Czechoslovakian citizen. Only about 20 Warsaw Pact members lost their lives in the invasion. Most of the deaths among the Soviet troops came from the inevitable traffic accidents which accompany mass military movements. A small number of Soviet soldiers were executed by firing squad for refusing orders, and some few committed suicide. Both sides were surprised and elated that casualties were so few.

The Aftermath

Dubcek and his top officials received the standard communist treatment of prisoners they were not permitted to wash and were deprived of sleep. After a week, they returned home, with all but one having signed an agreement agreeing to the temporary presence of Soviet troops on Czechoslovakian soil. Because the hard-liners failed to deliver their promised “provisional revolutionary government of workers and peasants” in conjunction with the invasion, the Soviets were forced to reinstate Dubcek as head of the Czechoslovakian government. Back in power for but a brief time, Dubcek attempted to preserve the achievements of the Prague Spring, apparently without much success.

Replaced as first secretary by Gustav Husak, Dubcek was put to work as a forester, repairing chain saws for his livelihood. Thousands lost their jobs in the political purges which inevitably followed, and because it was illegal to be unemployed, many of the country’s intellectuals were put to toiling at menial jobs. Half a million people were expelled from the Communist Party, and some 150,000 Czechs fled the country.

Another Intelligence Failure?

Whenever an unexpected international event occurs, we Americans are prone to scream “Another intelligence failure!” Did the Warsaw Pact invasion of Czechoslovakia to crush the Prague Spring constitute an intelligence failure? Well, yes and no. As we have seen, the strategic information [redacted text]

Former NSA historian Tom Johnson cites “a modem day scholar” who suggested that, had DIA possessed in 1968 the warning system that it later developed, it would almost certainly have issued a warning: report by 19 August, Force posture reported [redacted text] was certainly at the highest level ever achieved, higher even than that of May and June. According to Johnson, the failure to publish a warning report was because the system for doing so had not yet evolved.

Perhaps Angelo Codevilla characterized the situation best:

“As the U.S. tried to figure out whether or not the Soviets would invade Czechoslovakia in 1968, these [SIGINT] reports quite simply muddied the water and [challenged] even the most experienced all-source analyst searching for meaning in patterns in a mountain of material. The -conversations reported were relevant. There were just too many.”

Source: NSA