One way to sort this out would be to conduct a statistically valid comparison of fetal survival rates across countries. In each country to be studied, take a random sample of pregnancies that are normal as of three months. Try to control for age of the mother and other risk factors. Then measure the proportion of babies that live to age one.
A statistical study of this sort would not be affected by some of the measurement differences that I suspect are in the aggregate infant mortality data. I am not saying that such a study would prove that the cabal is wrong. However, it would provide what for me would be more persuasive evidence, regardless of whether the results imply that that U.S. health care is better, worse, or the same as that of other countries.
Paul Krugman and others are jumping to the conclusion that the U.S. has an inefficient health care system, based on data that were never intended to be used to make international comparisons. The purpose of the essay is to suggest that the issue should be studied first and decided later, rather than the other way around.