Russia may be capitalist but they don't quite "bend the knee" to US geopolitical interests, I think that's the issue. Countries like the UK, Germany, Japan... they have some nominal freedom to guide their own foreign policy but when it comes to stuff that really matters, when have any of the US-aligned nations seriously challenged US imperialist foreign policy? The Iraq invasion, for example... even the allies that didn't buy in like the UK did more or less kept their mouths shut the whole time. Russia doesn't play along so they need to be "brought to heel", so to speak. Why now specifically though, idk.