They absolutely thought they could force a regime change in Russia when the war started. Recall all the whole rouble will be rubble nonsense. The plan was to isolate Russia economically using sanctions and intimidate countries into not trading with Russia. Then Russian economy was supposed to collapse and people were gonna overthrow the government. This is why Europe went all in on the whole thing, they thought they're gonna ride it out for a few months and then they'd get to plunder Russia after that.
Of course that's not how it went, and that's when US started shifting towards the strategy of trying to make Russia bleed as much as they could. Europe ended up stuck following US even as it became clear that economic damage for Europe would be enormous.
Now, it's starting to become clear that the west failed to break Russia economically, and far from being weakened we're seeing a much stronger and more assertive Russia emerge backed by the Global South. This is the worst possible outcome for the west, and Europe in particular.