If the EU coordinates with the US, Japan, and all larger economies (perhaps via IMF), couldn't they still force Greek out of any currency their assets are cashe

If the EU coordinates with the US, Japan, and all larger economies (perhaps via IMF), couldn't they still force Greek out of any currency their assets are cashed out into? The incentives of other countries to go along is the prevention of contagion economic depression. Of course, Greece could still convert them into a currency not controlled by this coalition (Zimbabwean dollar? ;-)), but small currencies in this role cannot support Greek economic downfall and will be significantly affected by Greek economic results. This will still accomplish the goal of getting Greece to take responsibility for their economic decisions. (If the only choices are smaller currencies, Greece will probably choose to set up their own currency instead.)