As the introduction to this book makes clear, so much Vietnam War historiography, both popular and academic, is about assigning blame for the losses, both political and personal. Was it Kennedy or Johnson, hawks or doves, a conscious choice or a historical inevitability? Particularly when this book was written in 2005, at the height of the Iraq War, the question of political responsibility for a war going badly was particularly acute.

Counterfactuals are somewhat absurd. History is a matter of interpreting evidence, but there is only one past. The methodological dispute between counterfactual and virtual history is somewhat arcane, but the method here has some validity. Blight and his co-authors assembled a panel of about 20 distinguished individuals: 3 Kennedy-Johnson officials (low level ones, the only one I'd heard of was Bill Moyers, and that's because he's been a newscaster for decades since being LBJ's press secretary), and evenly matched teams of 'skeptical' academics who believe Kennedy would have acted much as Johnson did, and 'radical' academics who thought he would have done differently, had he lived. Participants read a 1000 page briefing document of mostly primary sources, a selection of which are at the back, and then met for three days of spirited discussion at the Musgrove Conference Center in Georgia.

The book consists of a mix of summarizing commentary by the authors, direct quotes of participants, and primary sources, and is therefore most immediately useful as a model of how historians debate. The questions focused on three key moments in 1961, as Kennedy decides whether to commit to Laos, 1963 as Kennedy decides to remove Diem from power in a CIA-orchestreated coup, and then "long 1964", where Johnson starts Operation Rolling Thunder and eventually deploys the Marines to Da Nang.

The matter of Kennedy vs Johnson is a fascinating one, because the two men were of the same party, had comparable attitudes on muscularly interventionist anti-Communism, and practically the same foreign policy team. The differences, as the skeptics argue, were in psychology and foreign policy expertise. Having been burned by trusting hawkish advisors during the Bay of Pigs, and gained confidence during the Berlin Crisis and Cuban Missile Crisis, Kennedy was more confident in foreign policy, and more skeptical of good military outcomes. Additionally, while the foreign policy team (Robert McNamara, Walt Rostow, McGeorge Bundy, Dean Rusk, etc) was very similar, Kennedy was better at tolerating internal dissent and going against his advisors. Finally, assuming that South Vietnam was teetering on the brink of collapse in 1965, Kennedy would be in his second term and much less vulnerable to public pressure of the 'Who lost China?' variety.

The radicals lay out an argument that Kennedy has made a private decision to limit the American commitment to Vietnam to advisors only, and that he was prepared to let South Vietnam fall before sending in American troops. The skeptical counter is that while this private decision may be in character for Kennedy, there's no actual evidence of it, even in masses of private letters and audio tapes, that Kennedy did massively escalate the advisory commitment between his inauguration and assassination, and that decisions about 'withdrawal' may have been a token 1000 advisors, who were in fact withdrawn and replaced with a new set of 1000 advisors, out of roughly 17000 Americans in-country at the start of 1964.

There's no argument that Johnson made the war a psychological referendum on his own character and resolve, and that he and his administration agonized over the decision for months, while Johnson and Walt Rostow worked tireless to suppressing dissenting views. Ultimately, we'll never have an answer to this question, but the key lesson is that a short victorious war isn't.