If we could not bring the birth rate down, it really was incumbent upon us to bring the death rate back up?
It's our "realpolitic" is what smacks of utopian Planning and Population Control where the utterly immoral is rationalized as some pragmatic necessity.
One can debate whether or not population control will actually do what he claimed. But once people believe it will you can toss morality out the window.
Notice also that no one is too particular about the choice of methods.
Don't blame me. I'm not Kissinger, or Machiavelli, or any of the countless others who've made similar observations. I merely happen to think their observations are a correct description of human nature and its workings.