That sounds kinda stupid. These days when someone says something ridiculous but pro-war it generally turns out they are just lying through their teeth and just not being honest about their motivations (eg, getting kickbacks or they're worried about tactical political issues). It seems more than likely that when Kissinger writes that we're reading someone being dishonest.
In addition, I'm struggling with the idea that Kissinger of all people cared enough about what happened to Vietnamese people for it to affect policy. He was the sort who would have no difficulty at all allowing bloodbaths to happen if he thought that was advantageous. His wiki page suggests, in fact, that he did do exactly that a few times.
