Pacta Sunt Servanda: A Byzantine Fault Tolerant Commitment System for Sovereign States

Abstract. A purely institutional form of international commitment would allow sovereign states to make economic promises that their successors cannot cheaply break. Treaties provide part of the solution, but the main benefits are lost if en- forcement still depends on the goodwill of the parties themselves: pacta sunt ser- vanda — the foundational maxim that agreements must be kept — has remained, for two centuries of Latin American history, a principle without a mechanism. We propose a solution to the sovereign commitment problem using a permissioned 1Byzantine Fault Tolerant ledger operated by the member states themselves, cou- pled to a supranational custody and audit entity holding title to pledged commodity reserves, against which tokenized claims on audited production are issued into dol- lar capital markets. Validator power is not granted by treaty negotiation but earned through measured contribution — collateral escrowed, trade settled, promises hon- ored, infrastructure used — and is automatically reduced, together with escrowed collateral, upon verified default. The system tolerates up to one-third of its mem- bers behaving arbitrarily or maliciously without corruption of the record, requires a two-thirds supermajority to finalize any entry, and rebalances power on a timescale deliberately slower than any member’s electoral cycle. Defection ceases to be a diplomatic dispute and becomes a same-day repricing event. The network cannot make governments honest; it makes their dishonesty trade in real time, which is sufficient.