Cassidy makes an obvious but essential point:
At the start of the wars in Korea, Vietnam, and Iraq, fewer than one in four respondents to the Gallup survey believed it was a mistake to send in U.S. military forces. Thereafter, though, this number steadily increased. By the time the wars had been going on for two or three years, more than fifty per cent of respondents said that the decision to wage them had been an error. The one exception was Afghanistan, where, after three years of war, the percentage of people describing the decision to dispatch U.S. forces as a mistake was still pretty small. Since then, though, this figure has grown: by 2012, it was close to fifty per cent.
Larison wonders how Americans will support the war:
In most cases, the near-instant bipartisan consensus that congeals around an interventionist policy and the attendant media demands to “do something” tend to drown out countervailing arguments during the first few months of the campaign. This boosts public support for military action in the short term, but like any bait-and-switch trick it also causes people to sour on the intervention more quickly than they might have done otherwise. More Americans gradually become aware that the threat to the U.S. was overstated (or simply made up) all along, and they start to realize that the war they were originally told about at the beginning is not the one that the U.S. is actually fighting. Because presidents often set unrealistic goals for these interventions, there is usually even greater disillusionment because the war comes to be seen as “not working.” That is a trap that presidents set for themselves. They are the ones promising results that aren’t possible, and those results certainly aren’t possible at the very low cost that the public is willing to accept.