After two years at the head of the Vichy government, Admiral Darlan was unpopular and had strengthened ties with Vichy forces, in an expanded collaboration with Germany which seemed to him the least bad solution, and had conceded a great deal, turning over the naval bases at Bizerte and Dakar, an air base in Aleppo in Syria, as well as vehicles, artillery and ammunition in North Africa and Tunisia, in addition to arming the Iraqis. In exchange Darlan wanted the Germans to reduce the constraints under the armistice, free French prisoners, and eliminate the "ligne de démarcation". This irritated the Germans. On 9 March 1942, Hitler signed a decree giving France a chief of the SS and police leader (HSSPF) tasked with organizing the "Final Solution", following the Wannsee Conference with the French police. The Germans demanded the return of Laval to power, and broke off contact. The Americans intervened on March 30 to prevent another Laval administration.