An orderly sale of Italy's state-owned industries and Greece's land holdings would take time, which is no longer available, so the immediate solution to the crisis is to place such hard assets in a euro-zone trust that would then issue euro-zone bonds backed by those assets.
What made 2011 so toxic in the euro zone was the widespread breakdown in trust: Trust between governments, within governments and between governments and voters.
And enshrining limits on borrowing and debt levels in national constitutions doesn't seem a bad way of restoring trust in the financial management of euro-zone governments, which don't have a great deal of credibility left.