We present a dynamic model of international lending in which borrowers cannot commit to future repayments and in which debtors can sometimes successfully negotiate partial defaults or "rescheduling agreements." All parties in a debt rescheduling negotiation realize that today's rescheduling agreement may itself have to be renegotiated in the future. Our bargaining-theoretic approach allows us to handle the effects of uncertainty on sovereign debt contracts in a much more satisfactory way than in earlier analyses. The framework is readily extended to analyze the conflicting interest of different lenders and of banks and creditor country taxpayers.