all three countries. Following Japan's attack on Pearl Harbor and in compliance with its Axis commitment, Romania declared war on the United States within five days. These developments contrasted with Antonescu's own statement of 7 December: "I am an ally of the [German] Reich against [the Soviet Union], I am neutral in the conflict between Great Britain and Germany. I am for America against the Japanese." A crucial change in the war came with the Battle of Stalingrad in June 1942 – February 1943, a major defeat for the Axis. Romania's armies alone lost some 150,000 men (either dead, wounded or captured) and more than half of the country's divisions were wiped out. The loss of two entire Romanian armies who all either killed or captured by the Soviets produced a major crisis in German-Romanian relations in the winter of 1943 with many people in the Romanian government for the first time questioning the wisdom of fighting on the side of the Axis. Outside of the elites, by 1943 the continuing heavy losses on the Eastern Front, anger at the contempt which the Wehrmacht treated their Romanian allies and declining living standards within Romania made the war unpopular with the Romanian people, and consequently the Conducător himself. The American historian Gerhard Weinberg wrote that: "The string of broken German promises of equipment and support, the disregard of warnings about Soviet offensive preparations, the unfriendly treatment of retreating Romanian units by German officers and soldiers and the general German tendency to blame their own miscalculations and disasters on their allies all combined to produce a real crisis in German-Romanian relations." For part of that interval, the Marshal had withdrawn from public life, owing to an unknown affliction, which is variously rumoured to have been a mental breakdown, a foodborne illness or a symptom of the syphilis he had contracted earlier in life. He is known to have been suffering from digestive problems, treating himself with food prepared by Marlene von Exner, an Austrian-born dietitian who moved into Hitler's service after 1943. Upon his return, Antonescu blamed the Romanian losses on German overseer Arthur Hauffe, whom Hitler agreed to replace. In parallel with the military losses, Romania was confronted with large-scale economic problems. Romania's oil was the Reich'''s only source of natural oil after the invasion of the Soviet Union in June 1941 to August 1944 (Germany also had synthetic oil plants