The problem is circular. The risk is that your counterparty goes bust. Therefore nobody wants to make any moves until they can be sure that (mostly) every other player is stable. But because no moves are happening, that in itself is destabilizing.

That is, the big risk is "what if the state doesn't intervene?"

Correspondingly, the state has a special move that only it can play, because "what if the state doesn't intervene" is not a risk to the state itself. The act of intervening makes the risk go away. That's part of the privilege of being the lender of last resort with the option to print currency.

(which is why this was a much more serious problem for Greece and Ireland, which as Eurozone members were constrained in their ability to even contemplate printing their way out of the problem!)