This is exactly the kind of war that is most unlikely to happen between two liberal democracies[1] according to democratic peace theory[2]. Only a leader whose interests are distinct from the public and who can work without legal constraints can make a personal error of this magnitude.

There is no real animosity nor cause for the war between Ukraine and Russia. Both countries lose big in this war.

[1]:liberal democracy: democracy with separation of powers, an independent judiciary and a system of checks and balances between branches of government.

[2]: Democratic peace theory https://en.wikipedia.org/wiki/Democratic_peace_theory