Naulilaa arbitration (1928)

The Naulilaa arbitration (1928) was a German-Portuguese claims award concerning German attacks in Portuguese Angola after an October 1914 frontier incident. It is frequently cited for conditions governing historical reprisals. Modern countermeasure law developed later and excludes armed force; the award is not authority for a present right to conduct armed reprisals.

Dispute and award

German officials were killed at Naulilaa while Portugal remained neutral. German forces subsequently attacked Portuguese posts and characterised their action as reprisal. The tribunal found that the original incident was not an internationally wrongful act attributable to Portugal. It also found no prior demand for redress and treated the German response as excessive.

In explaining reprisals, the award identified a prior wrongful act, an unsatisfied demand and proportionality as relevant conditions. Its terminology belonged to the law of its period. It did not state the complete modern framework and should not be converted into a timeless three-part test detached from later law.

Modern boundary

The International Law Commission's 2001 Articles treat countermeasures as temporary non-performance directed at inducing a responsible state to comply with its obligations. They add requirements concerning notice, an offer to negotiate, proportionality, termination and protected obligations. Countermeasures may not affect the prohibition on force, fundamental human rights, humanitarian obligations prohibiting reprisals or peremptory norms. The International Court of Justice's judgment in Gabčíkovo-Nagymaros also addressed necessity, prior wrongfulness and proportionality in the modern setting.

Editors should distinguish countermeasures from retorsion, which is unfriendly but lawful conduct, and from measures authorised by an international organisation. Historical Reprisals Orders in Council (UK, 1915 and 1917) require their own legal assessment. The Naulilaa award supplies an important line of doctrinal development, not a conclusive licence for contemporary economic coercion.

See also

Countermeasures under the ILC Articles on State Responsibility (2001) · Reprisals Orders in Council (UK, 1915 and 1917) · Article 16 of the League of Nations Covenant (1919) · Normative constraints on economic warfare

Sources

1. United Nations, Reports of International Arbitral Awards, volume II (accessed 30 July 2026).
2. German-Portuguese Arbitral Tribunal, *Naulilaa*, award, pp. 1011 to 1037 (31 July 1928).
3. International Law Commission, Articles on Responsibility of States for Internationally Wrongful Acts, with commentaries (2001).
4. International Court of Justice, *Gabčíkovo-Nagymaros Project*, case 92 (accessed 30 July 2026).