The Russians have referred it yesterday to, I think, one of their Moscow courts. A preamble if you like. The most interesting courts they are likely to refer to thereafter are in Singapore and Hong Kong (I think EuroClear has a couple of trillion in each of these) and in perhaps an Arab country. Speculating here.

Presumably EU countries have rather a lot of assets in Russia that could be appropriated in response?

It doesn't really match the ginormous amount of Russian assets in EuroClear. We'll see.

I think it likely the case might last a decade or two. Meanwhile thrashing the EU as a bastion of Mafia capitalism and diminishing/crashing their role as a safe haven for investments. EU 'democracy' in charge, in the shape of highly paid bureaucratic political elite wanting war at all costs to stay in power. Myopia abounds.

It could be worse : )