no politician gets what she/he wants. They can only go upwind. The structural forces - like strategic interests - are forcing the decisions on them. They can move one inch left or right, but that's about it. It doesn't matter if this is a democracy or regime. You can observe it now, when Biden is continuing Trump's policies like trade tariffs on China.
No one wants a war, but if the stability of the system depends on it you are forced to act. I think this war is similar to Opium Wars. Without the trade British Empire would have serious problems.
The world is decarbonising and more than half of RF income comes from natural resources. Putin needed a better position to secure the future of Russian Federation. He tried to use the argument of force in a 3 day war, but the gamble didn't work.