War is the biological imperative to grow, to expand as a society, versus a finite world inhabited by other societies.

As Catherine the Great, of Russia said, "The only way I seem to be able to stabilize my borders is to expand them.

For those who actually follow the news and not just the propaganda, Putin was faced with the same quandary. Nato insisted on expanding like bacteria across a petri dish and he had to clarify the dish had a side.

Here is a good treatise on the politics, by someone with diplomatic experience;

https://aurelien2022.substack.com/p/war-peace-and-that-other-thing