By the late 1990s, the term WMD was an integral part of American national security discourse, as evident by its growing usage. A full text search of the New York Times identified the number of stories every year from 1945 to 2010 using the term WMD or a variant. Other than 1973, the term appeared in at least one article every year during that 65-year period. During the late 1940s and early 1950s, it appeared in stories about 30 times every year, declining to an average of only 20 a year in the late 1950s and the 1960s. There were fewer than nine stories every year on average during the 1970s and 1980s. In other words, contrary to common belief, the term was more common at the start of the Cold War than at the end. After the end of the Cold War, however, the term saw increasing usage. It appeared an average of more than 100 times a year in the early 1990s and an average of 160 times a year in the late 1990s (peaking at 370 appearances in 1998). Heaviest use of the term WMD occurred during and after the 2003 invasion of Iraq: 1,069 stories in 2003 and 632 stories in 2004. Indeed, it appeared so often in 2002 and 2003 that WMD made lists of the most used or overused phrases. After that, the frequency declined precipitously, and now appears to have returned to about the same average rate as found during the late 1990s. Although often associated with the administration of George W. Bush, his two predecessors also used it extensively. Despite the extensive use of the term during the past two decades, there is a widespread perception that it has no accepted definition and that it means whatever the user wants it to mean.