The origin of the term "leader of the free world" is somewhat uncertain. Dominic Tierney of The Atlantic tracked it back to a 1948 New York Times article, in which British economist Barbara Ward called upon the U.S. to lead the West in fighting the communist threat. But a Google Books search suggests the title was first used during World War I and has made regular appearances in English-language books since the late 1930s. In any case, its use surged at the peak of the Cold War in the early 1960s (when Soviet leader Nikita Khrushchev began referring to "the free world" with heavy irony), declined toward the detente of the mid-1970s, then gained again through the Soviet Union's collapse and up until its last peak in 2007, just before the global financial crisis.