Given that they want to steal Russian assets because they've run out of money to fund the war, it's not clear where the money to compensate Euroclear would come from. However, that's not really even the main issue. The real risk is that Europe becomes toxic to foreign investment once they do this. Nobody in their right mind would ever park money in Europe or invest into European industry after that. The whole attempt to seize Nexperia doesn't help build confidence either. And of course, foreign money that's currently in Europe is going to flee as well which will lead to a huge financial crisis bringing us back to the question of how the EC can possibly reimburse anything.