Switzerland's trade was blockaded by both the Allies and by the Axis. Economic cooperation and extension of credit to the Third Reich varied according to the perceived likelihood of invasion and the availability of other trading partners. Concessions reached a peak after a crucial rail link through Vichy France was severed in 1942, leaving Switzerland completely surrounded by the Axis. Over the course of the war, Switzerland interned over 300,000 refugees and the International Red Cross, based in Geneva, played an important part during the conflict. Strict immigration and asylum policies as well as the financial relationships with Nazi Germany raised controversy, but not until the end of the 20th century.