James Taranto:

Barack Obama’s latest pronouncement on Iraq should have shocked the conscience. In an interview with the Associated Press last week, the freshman Illinois senator and Democratic presidential candidate opined that even preventing genocide is not a sufficient reason to keep American troops in Iraq.

“Well, look, if that’s the criteria by which we are making decisions on the deployment of U.S. forces, then by that argument you would have 300,000 troops in the Congo right now–where millions have been slaughtered as a consequence of ethnic strife–which we haven’t done,” Mr. Obama told the AP. “We would be deploying unilaterally and occupying the Sudan, which we haven’t done. Those of us who care about Darfur don’t think it would be a good idea.”

Mr. Obama is engaging in sophistry. By his logic, if America lacks the capacity to intervene everywhere there is ethnic killing, it has no obligation to intervene anywhere–and perhaps an obligation to intervene nowhere. His reasoning elevates consistency into the cardinal virtue, making the perfect the enemy of the good.

Further, he elides the distinction between an act of omission (refraining from intervention in Congo and Darfur) and an act of commission (withdrawing from Iraq). The implication is that although the U.S. has had a military presence in Iraq since 1991, the fate of Iraqis is not America’s problem.

And what about Vietnam after we left?

In his June 1971 debate with fellow swift boat veteran John O’Neill on “The Dick Cavett Show,” the 27-year-old Mr. Kerry said, “There’s absolutely no guarantee that there would be a bloodbath. . . . One has to, obviously, conjecture on this. However, I think the arguments clearly indicate that there probably wouldn’t be. . . . There is no interest on the part of the North Vietnamese to try to massacre the people once people have agreed to withdraw.” Mr. Kerry acknowledged that “there would be certain political assassinations,” but said they would number only “four or five thousand.”

Here is what did happen:

According to a 2001 investigation by the Orange County Register, Hanoi’s communist regime imprisoned a million Vietnamese without charge in “re-education” camps, where an estimated 165,000 perished. “Thousands were abused or tortured: their hands and legs shackled in painful positions for months, their skin slashed by bamboo canes studded with thorns, their veins injected with poisonous chemicals, their spirits broken with stories about relatives being killed,” the Register reported.Laos and Cambodia also fell to communists in 1975. Time magazine reported in 1978 that some 40,000 Laotians had been imprisoned in re-education camps: “The regime’s figures do not include 12,000 unfortunates who have been packed off to Phong Saly. There, no pretense at re-education is made. As one high Pathet Lao official told Australian journalist John Everingham, who himself spent eight days in a Lao prison last year, ‘No one ever returns.’ ” The postwar horrors of Vietnam and Laos paled next to the “killing fields” of Cambodia, where the Khmer Rouge undertook an especially vicious revolution. During that regime’s 3 1/2-year rule, at least a million Cambodians, and perhaps as many as two million, died from starvation, disease, overwork or murder. The Vietnamese invaders who toppled the Khmer Rouge in 1979 were liberators, albeit only by comparison.In the aftermath of America’s withdrawal from Vietnam, hundreds of thousands of refugees fled Vietnam, Cambodia and Laos. According to the U.N. High Commissioner on Refugees, between 1975 and 1995 more than 1.4 million Indochinese escaped, nearly 800,000 of them by boat. This does not include “boat people” who died at sea, 10% of the total by some estimates.