With the outbreak of World War II, Liberman fled to the United States together with his future wife, Tatiana Yacovleff Du Plessix. Always well-connected, he soon took the post of art director at Vogue, reshaping the look and layout of every publication he touched. Twenty years later Alexander reached the role of Editorial Director at Condé Nast Publications, where he stayed for another thirty-two years. During that period, he was responsible for the look, style and content of Vogue, Mademoiselle, Glamour, Bride's and House & Garden—five of the most popular women's magazines in the US, with a total readership of more than five million.