additional protocol I

Additional Protocol I (AP I) is a 1977 treaty that supplements the four Geneva Conventions of 1949, expanding international humanitarian law (IHL) to govern the conduct of hostilities in international armed conflicts. It was adopted on 8 June 1977 at the Diplomatic Conference convened by the Swiss Federal Council in Geneva and entered into force on 7 December 1978.

The Protocol codifies and develops several core IHL principles, most notably:

• Distinction (Article 48) — parties must at all times distinguish between civilians and combatants, and between civilian objects and military objectives.
• Proportionality (Article 51(5)(b)) — attacks expected to cause incidental civilian harm excessive in relation to the concrete and direct military advantage anticipated are prohibited.
• Precautions in attack (Article 57) — commanders must take feasible measures to verify targets and minimize civilian harm.
• Protection of civilian objects, cultural property, and the natural environment (Articles 52–56).
• Prohibition of perfidy and misuse of protective emblems (Articles 37–39).

AP I also extended the definition of international armed conflict in Article 1(4) to include wars of national liberation against colonial domination, alien occupation, and racist regimes — a provision that proved politically contentious. It clarified combatant and prisoner-of-war status (Articles 43–44) and established the International Humanitarian Fact-Finding Commission under Article 90.

As of recent ICRC tallies, AP I has been ratified by the large majority of states, though several major military powers — including the United States, Israel, India, Iran, Pakistan, and Turkey — are not parties. The US signed in 1977 but has not ratified, citing concerns about Article 1(4) and combatant criteria. Nonetheless, many of AP I's provisions are widely regarded as reflecting customary international law, and the ICRC's 2005 customary IHL study found numerous AP I rules binding on all states regardless of ratification.

AP I is paired with Additional Protocol II, which addresses non-international armed conflicts, and Additional Protocol III (2005), which introduced the Red Crystal emblem.