Haunting questions remain about our involvement in Vietnam. Perhaps the most persistent of these is whether President Kennedy would have ended American involvement in Vietnam if he had lived.

For many Americans, Oliver Stone's film JFK left no doubt that before his assassination Kennedy had determined to quit Vietnam. Yet the historical record offers a more complex answer. In this fresh look at the archival evidence, noted scholars take up the challenge to provide us with their conclusions about the early decisions that put the United States on the path to the greatest...