Operation Unthinkable was the idea of Winston Churchill. He had been angered that the Red Army had been allowed to advance into Berlin unchallenged by the armies of the Allies. His response to this was Operation Unthinkable – on paper a plan that seemingly appeared to be ludicrous. Yet it was one that was briefly looked at again as the Cold War developed in Europe.


Winston Churchill had no love for communism. He also did not trust Joseph Stalin. When these two things were combined, Churchill made it plain that he did not trust Soviet intentions once the war was over – regardless of what Stalin has promised. He had already broken the promises he made at the Yalta conference when it was clear that as the Red Army moved west, puppet communist governments were put into power – governments that were loyal only to Moscow.


Churchill summed up his feelings on the issue in a letter to his Foreign Secretary Anthony Eden:


“Terrible things have happened. A tide of Russian domination is sweeping forward. After it (the war) is over, the territories under Russian control will include the Baltic provinces, all of eastern German, all Czechoslovakia, a large part of Austria, the whole of Yugoslavia, Rumania and Bulgaria. This constitutes one of the most melancholy events in the history of Europe and one to which there has been no parallel. It is to an early and speedy showdown and settlement with Russia that we must now turn our hopes.”


Within days of the war in Europe ending, Churchill surprised his Chiefs-of-Staff by enquiring whether an Anglo-American force could force back the Red Army from the River Elbe. He requested that military planners come up with a plan that could also include using German personnel and what was left of Germany’s economic might. He even thought of a date for such an assault – July 1st 1945. The Chief of the Army, General Sir Alan Brooke, was appalled at the plan and likened the Prime Minister to a warmonger. Brooke noted in his diary that Churchill was “longing for another war”.


One of the reasons that made Churchill so bellicose was the fact that he knew about the Manhattan Project and how close America was to developing atomic bombs passed the test phase. He even told Brooke that if Stalin failed to listen to the West’s wishes, the US could target Moscow, Stalingrad and then Kiev.


Military planners did carry out a feasibility study regarding an attack on Soviet forces in Poland. This highly sensitive document was called “Operation Unthinkable”. However, Stalin quickly knew about it such was the extent of his spy network in London. The key was when Field Marshal Montgomery was told to stockpile captured German weapons in case they were needed “for future use”.


Those who compiled the report made it clear their misgivings and the shortcomings Operation Unthinkable had. They estimated that the Allies would need 47 divisions to attack the Red Army; 14 of these would have to be tank divisions. A two-pronged attack was envisaged – one to Stettin and the other to Poznan. 10 reformed German divisions were also brought into the equation along with 10 Polish divisions already in Poland. A further 40 divisions would have to be held in reserve. To balance this, the planners informed Churchill that the Soviets could muster twice as many men and tanks as the Allies could. They concluded that any attack would be “hazardous” and that the campaign would be “long and costly”. The report actually stated: “If we are to embark on war with Russia, we must be prepared to be committed to a total war, which would be both long and costly.”


Brooke wrote that “the chances of success (are) quite impossible”.


Churchill received a draft copy of the plan on June 8th. The plan made it clear that the USA would have to give full support to Britain and that this could not be guaranteed. This seems to have brought Churchill to his senses and he wrote in the margin of the draft that an attack on the Red Army “was a highly improbable event.” He later changed these words to “purely hypothetical contingency”. Shortly afterwards, he received news from President Truman that made it clear that America wanted no part in Operation Unthinkable. The file was closed.


Churchill was full of misgivings about what the Soviet Union would do to its satellite states. However, his electoral defeat in 1945 removed him from power and ‘Operation Unthinkable’ was effectively buried once Churchill left Downing Street. However, just one year later senior American military figures were sufficiently worried about the growth of Soviet military strength that Operation Unthinkable was brought out of the vaults and looked at again. In May/June 1945, many of those who knew about Unthinkable believed (except Churchill) that the plan was the result of someone who had been in power for too long. Yet just one year later, turmoil in Europe had pushed American planners along the same road that Churchill had gone down one year earlier.