We live in an era where the global capital markets are the super power in the world, and when they move against you as they've moved against Russia, as we've all seen in the ruble, there's nothing that can stop that.
If a lending institution is faced with bids for a package of toxic assets that are less than the carrying value of those assets, the sale of those assets would trigger a further loss and reduce the underlying capital of the institution.
Russia's oil fields are mature and require capital and Western technology even to keep production flat.
The long-standing wisdom that everyone wins in a single world market has been undermined. Global trade, capital flows, and immigration are declining.