In December 1941, the United States entered World War II, and Marlene became one of the first celebrities to help sell war bonds. She toured the US from January 1942 to September 1943 (appearing before some 250,000 troops on the Pacific Coast leg of her tour alone) and was reported to have sold more war bonds than any other star. During two extended tours for the non-profit United Service Organizations Marlene – along with others such as comedians and musicians – provided live entertainment.
In 1943 Marlene assumed the honorary rank of Colonel in the American Army and began to make radio broadcasts – and then to make personal appearances on behalf of the American war effort.
In 1944 and 1945, Marlene performed for Allied troops in North Africa, Italy, France and the UK. She also went into Germany – her place of birth – with Generals James Gavin and George Patton. When asked why she had done this, in spite of the obvious danger of being within a few kilometres of German lines, she replied, “aus Anstand“—“out of decency”. Wilder later remarked that she was at the front lines more than Eisenhower!
Her revue, with Danny Thomas as her opening act for the first tour, included songs from her films, performances on her musical saw – a skill she had originally acquired for stage appearances in Berlin in the 1920s – and a “mind reading” act that her friend Orson Welles had taught her for his Mercury Wonder Show. Marlene would inform the audience that she could read minds and ask them to concentrate on whatever came into their minds. Then she would walk over to a soldier and earnestly tell him, “Oh, think of something else. I can’t possibly talk about that!”
American church papers reportedly published stories complaining about this part of her act. Right or not – in 1944, the Morale Operations Branch of the Office of Strategies Services (OSS) initiated the Musak project – a musical propaganda broadcasts designed to demoralize enemy soldiers. Marlene was the only performer who was made aware that her recordings would be for OSS use. A number of songs were made in German for the project and included “Lili Marleen”, a favourite of soldiers on both sides of the conflict. Major General William J Donavan, the head of the OSS, wrote to Marlene, “I am personally deeply grateful for your generosity in making these recordings for use.”