In 1977, driven by developments in armed conflict subsequent to the Second World War, there was a major revision and updating of the Geneva Conventions. Two protocols to the Conventions, one dealing with international armed conflict, the other dealing with non-international armed conflict, were adopted at a diplomatic conference convened by the Swiss Federal Council. The existence of the two protocols, and the distinctions between them, highlight the importance of the issue of thresholds of armed conflict with respect to the implementation of international humanitarian law. In a number of respects, the two Additional Protocols refine and complicate issues relating to the determination of the existence of armed conflict.

This chapter, in two parts, examines each of the two Protocols. The first part studies Additional Protocol I, which is devoted to international armed conflict, demonstrating the way in which the concept of non-international armed conflict was narrowed to exclude wars of national liberation. The second part scrutinises Additional Protocol II, which addresses non-international armed conflict, paying specific attention to provisions governing its application. While the two new categories of armed conflict created by the Additional Protocols are considered not advantageous to the implementation of international humanitarian law, it is contended that the distinctions introduced in these instruments do not represent codifications of customary international law. It is also held that they do not affect the threshold of application associated with common Article 3.