Sovereign immunity has served as a partial substitute for bankruptcy protection, but it has encouraged a minority of creditors to pursue unorthodox legal remedies with spillover effects far beyond the debtor-creditor relationship. The attempt to enforce Argentina's pari passu clause in New York...

The Greek debt crisis prompted EU officials to embark on a radical reconstruction of the European sovereign debt markets. Prominently featured in this reconstruction was a set of contract provisions called Collective Action Clauses, or CACs. CACs are supposed to help governments and private...