## Facts

- Chile and Argentina disputed sovereignty over Picton, Lennox, and Nueva islands and related maritime/navigation rights in the Beagle Channel, amid ambiguity in an 1881 boundary treaty.
- In 1971, the states submitted the dispute to international arbitration by a tribunal appointed by the British Crown.
- In 1977, the arbitral award favored Chile; Argentina rejected it as null, while Chile treated it as binding.
- Bilateral negotiations failed, and by late 1978 both states mobilized for an impending armed conflict.
- Pope John Paul II initiated third-party involvement by sending Cardinal Antonio Samoré for emergency shuttle diplomacy.
- In January 1979, the states executed the Act of Montevideo, requesting papal mediation and committing to non-use of force during the process.
- The Holy See structured a multi-year mediation (1979–84), including extensive information gathering, agenda expansion beyond the islands, and high-level engagement by the Pope.
- The process culminated in the 1984 Treaty of Peace and Friendship, which maintained Chilean sovereignty over the islands while adjusting maritime boundaries and navigation arrangements to address Argentine concerns.

## Issues

1. How can a comparatively ad hoc, nonspecialist third-party effort succeed after formal legal and diplomatic mechanisms fail in a near-war setting?
2. What is the proper metric for “mediator effectiveness” in high-stakes international disputes: substantive legal/territorial optimality or the prevention of armed conflict?
3. How do a mediator’s institutional attributes—moral authority, perceived neutrality, and cultural/religious ties—shape strategy, leverage, and settlement durability?

## Decision

- The analysis concludes the Vatican’s mediation was effective because it averted imminent war and enabled a negotiated, treaty-based settlement.
- Effectiveness is framed primarily as “assuring peace,” rather than producing a legally elegant or expert-designed allocation of territory.
- The Vatican’s institutional position supplied leverage without coercive power, helping sustain party commitment to non-use of force and continued bargaining.
- The mediation’s process choices—extended listening, incremental agenda sequencing, and patience over time—are treated as central causal factors in achieving agreement.

## Legal Principles

- Mediator effectiveness in international disputes may be assessed against the mediator’s primary objective (e.g., preventing war and stabilizing relations), not solely against technical optimality of substantive terms.
- A mediator’s legitimacy and perceived neutrality can function as settlement-relevant resources comparable to material leverage, especially when parties share strong cultural or religious ties to the mediator.
- Enforceable process commitments by parties (including a pledge renouncing force) can be outcome-determinative by preserving a bargaining space during crisis escalation.
- Process design—beginning with areas of agreement, broadening the agenda, and allowing a longer horizon—can reduce zero-sum framing and make complex package deals feasible.
- In polarized disputes, durable settlement may require addressing linked issues beyond the immediate focal point (territory plus maritime delimitation and navigation regimes).

## Conclusion

The Vatican’s mediation is presented as a successful model of third-party intervention in a near-war territorial dispute, showing that legitimacy-based influence, non-use-of-force commitments, and patient, agenda-expanding process management can convert a deadlocked legal conflict into a durable peace treaty.


Princen, International Mediation—The View from the Vatican: Lessons from Mediating the Beagle Channel Dispute, 3 Negotiation J. 347 (1987)