On the list of agreements reached by the parties participating in the Tehran conference, Roosevelt presented a plan to distribute the country into several autonomous regions, with the main industrial and commercial centers under international control. Churchill felt that this was impractical and preferred instead a kind of north-south divide that weakened “preusism” at the expense of what he saw as the less militaristic and aggressive regions of southern Germany. Stalin saw things differently and said that all Germans were belligerent and infidian by propensity and that their country had to be permanently fragmented, with no possibility of reunification. We talked about what would happen after the war with Europe, but it was mainly about Germany. The agreement in principle, i.e. no formal agreement, was that only unconditional surrender would be accepted by the Allies. There was also the idea that German should be left as a weak nation after the war and that the lands that had conquered it during the expansion of Germany should be returned to the countries that had lost it. Although Churchill accepted this rather unusual regulation at first, it soon became regrettable when The British suspicions grew of Stalin in order to rally the situation to Roosevelt for his own way of thinking. In his own memoirs, the British Prime Minister recalled his obligation to seek a private interview with Stalin to complain that Roosevelt now seemed to avoid him and to counter what he saw as the Soviet leader`s attempts to divide the Anglo-American alliance by taking advantage of Roosevelt`s goodwill and what many consider to be naïve idealism in his handling of world affairs. When the German-Soviet war broke out in June 1941, Churchill offered aid to the Soviets and an agreement was signed on July 12, 1941.  However, in a radio broadcast in which he announced the alliance with the USSR, Churchill reminded listeners that this alliance would not change his attitude against communism.
 Delegations had travelled between London and Moscow to organize the implementation of this support, and when the United States joined the war in December 1941, delegations also met in Washington. A committee of team leaders was set up to coordinate British and American operations and their support for the Soviet Union. The consequences of a world war, the absence of a single allied strategy and the complexity of the allocation of resources between Europe and Asia have not yet been elucidated and have quickly led to mutual distrust between the Western Allies and the Soviet Union.  This was the opening of a second front to relieve German pressure on the Soviet Red Army on the Eastern Front, the issue of mutual assistance (where Britain and the Soviet Union sought both loans and material support to the United States and where there were tensions between the United States and Great Britain, with Washington not having the desire to support the British Empire in the event of an Allies` victory).  Neither the United States nor Great Britain were prepared to give Stalin carte blanche in Eastern Europe, and finally there was no common policy on how to treat Germany after Hitler. Communication on these issues between Churchill, Roosevelt and Stalin was via telegrams and emissaries – but it was clear that there was an urgent need to negotiate directly.  Iran went to war with Germany, a common enemy of the three powers.