The Art of War, Sun-Tzu's 4th century B.C. treatise on military strategy, says that the most important weapon in any nation's arsenal is spies, because spies contribute to foreknowledge, without which strategy is impossible. But what kind of spying is appropriate for a given situation? That is the overarching question posed by Peter Grose's Operation Rollback: America's Secret War Behind the Iron Curtain, a serious, workmanlike account of a little-known chapter in Cold War history that saw the United States conduct a secret, often violent war against Soviet domination of Eastern Europe in the late 1940s and early 1950s.

"It is one thing," Grose writes, "to dispatch an agent to sketch the pilings and struts of a strategic bridge but something else to have the agent plant an explosive charge under those pilings and struts," particularly because it takes years to build up an espionage network, which a "positive act of sabotage" can immediately destroy. After World War II, the United States decided on the second, more aggressive form of covert operation.

As soon as Stalin's hostile intentions toward his former wartime allies in the West became clear, the United States organized armed guerrilla groups composed of ethnic Balts, Albanians, Yugoslavs, Romanians and others--many with fascist backgrounds--to infiltrate the new satellite states and create disorder. The effort failed miserably. Many of the operations were penetrated by Soviet agents (including the Soviet double agent Kim Philby, posted to the British Embassy in Washington at the time). More significantly, the goal of toppling communist regimes was completely unrealistic, especially given the relatively small number of guerrillas and saboteurs assigned to the task.

As the author notes, there were ironies aplenty here. The "founding father" of this secret, military operation to "roll back" communism in Eastern Europe was George Kennan, whom most people associate with the more seasoned and moderate policy of containment laid out in his famous X article, in the July 1947 issue of Foreign Affairs. However, while Kennan's article was being skewered by conservative Republicans, who equated containment with appeasement, he was quietly setting up a clandestine network from his State Department offices. The Truman administration--which Republicans were then lambasting for its supposed softness toward communism--signed on to Kennan's plan for political and paramilitary warfare, even though the new Central Intelligence Agency and the Joint Chiefs of Staff were uncomfortable with it. It was a Republican president, Dwight Eisenhower, following Stalin's death in 1953, who ended Truman's and Kennan's aggressive campaign against the Soviets, the anti-communist rhetoric of Eisenhower's secretary of state, John Foster Dulles, notwithstanding.

Nevertheless, Grose shows that many New Deal Democrats were truly naive about communism and Stalin but that neither Kennan nor his State Department colleague Loy Henderson--both of whom had ground-level experience in the Soviet Union in the 1930s--was among them, even when Stalin was our ally during the war. Both men represented an intellectually brave cadre of foreign service officers who, despite being maligned by left-wing intellectuals at the time, consistently maintained that the moment the war was over Stalin would replace Hitler as our foe. And they were right, of course. This is not an unknown story--H.W. Brands covers Henderson's prescience in Inside the Cold War--but it deserves repeating.

Kennan's failed rollback operation did have some successes, but they were not of the military sort. For example, a naturalized American from Estonia, Michael Josselson, ran a flourishing covert operation that mobilized intellectuals in the West and the Third World to publish dozens of magazines and books against Marxism. This included Encounter, arguably the finest magazine published in the English language in the 20th century. There were also Radio Free Europe and Radio Liberty, both part of Kennan's original conception.

Grose's tone is usually cool and even-handed, rarely polemical. The only complaint I have is one of nuance. The author may be somewhat too hard on Kennan and the goal of rolling back communism. He writes that "Kennan's concept of a counterforce against Soviet power brought legitimacy to an old [anti-communist] jeremiad." There is a bit of smug hindsight here because it was unclear then just how firmly established the new communist regimes in Eastern Europe really were. History shows that a small, well-placed amount of pressure is most effective during times of flux, and the mid- and late 1940s were just such a period. If there ever was any hope of destabilizing the post-Yalta regimes in the East, it was following World War II, before they became solidified for decades. Of course, as Grose demonstrates (and as the British foreign secretary Ernest Bevin notes), the methods were amateurish and often irresponsible, even if the principle was fine.