Sanctions against Russia are completely ineffective because the US and the EU are unwilling to include things that would actually hurt Russia, namely access to the financial system (ie SWIFT), energy exports (because Germany in particular is dependent on Russian natural gas, the assets held by Russian kleptocrats).
On the security front, the EU woulld never accept Ukraine as a NATO member and the US won't put troops in Ukraine because that would put nuclear powers in direct conflict.
So given no effective sanction options and no military options, the US and the EU should've realized the only way to defuse this situation was to negotiate. Yet Biden categorically ruled out the possibility of formally refusing to admit Ukraine to NATO, something that was never going to happen anyway.
This situation bears some similarity to the US and Japan pre-WW2 actually. The US moved to block Japanese access to oil. That made war all but inevitable. I'm not saying the US was wrong there but it's just a consequence of that policy. LIkewise, leaving the door open to an anti-Russian military alliance expanding to the borders of Russia put Putin in a corner. Putin is still in the wrong here, straight up. But the options are to deescalate or World War Three. Given the invasion it's not much harder to negotiate out of this but what other option is there?
One thing I will say is that on the issue of seizing assets of Russian kleptocrats, real estate has long been a way of hiding money in developed countries. London real estate in particular is awash with Russian money. Maybe it's time we end anonymous ownership of property.