Cross-section samples in five states were asked in December 2004 and July 2005 whether the Iraq war is more like the Vietnam War or more like World War II. The Vietnam analogy was chosen disproportionately by those who were alive during that war, though the choice was not limited to exposure to the Vietnam period during what have been called the “critical years” of adolescence and early adulthood. The distinction between two forms of remembering, recall and recognition, helps situate the results with regard to past research on cohort effects on collective memory. Evidence is also presented against interpreting the present effect as related to the biological and social correlates of aging. Other results are included on the relations of analogy choice to partisan identification, gender, education, race, and region.