On this view, the only thing that can be done is to respond to asset and credit collapses if and when they occur, protecting where possible the financial system and the economy generally. That is, to clean up the mess afterwards, so to speak. This has tended to be the US official view, at least up until now.
The euro, in other words, conveys essential information which allows you to make price comparisons so that you can reach a decision. Money, in its capacity as a transmitter of information, performs a function similar to that of an international language. The greater the number of people who speak a language, the more it can facilitate communication. The same is true with money.