Kissinger wasn't a... socialist. Kissinger, was, compared to the people in charge today in the US, a remarkably effective and intelligent diplomat. He seems to have believed that it was preferable for great powers to channel their rivalry into conflicts confined to the 'stage' of smaller countries, almost on a 'symbolic' or 'sporting' level, and that this 'healthy competition' was far better than an open, dangerous and direct confrontation, which could get out of hand and lead to an existential war.
Now, morally, this is really bad for the smaller countries and their hapless populations, as thy are seen a pawns on a blood-soaked chessboard, which is how Kissinger saw the world. Kissinger wasn't an idealist or a moralist, but an arch realist, a cynical observer of the way of the world. He appears to have wanted to keep the 'necessary' level of violence within the bounds of the 'acceptable' and the 'realistic', because, seen from his perspective, the rivalry and violence between the great powers was always going to be there, the question was, how to manage it and restrict it to the 'stage' rather than see it escalate out of control. Not a 'nice' or particularly 'moral' way of acting; but perhaps better than the even more destructive alternatives?