Allied military personnel and civilian officials of the Allied forces could enter and exit East Berlin without submitting to East German passport controls, purchasing a visa or being required to exchange money. Likewise, Soviet military patrols could enter and exit West Berlin. This was a requirement of the post-war Four Powers Agreements. A particular area of concern for the Western Allies involved official dealings with East German authorities when crossing the border, since Allied policy did not recognize the authority of the GDR to regulate Allied military traffic to and from West Berlin, as well as the Allied presence within Greater Berlin, including entry into, exit from, and presence within East Berlin.