1.2.1 Hague Law and Geneva Law
The two parents: Hague law — the conduct-of-hostilities branch (the means-and-methods: the weapons' rules, the targeting's law; the 1899-and-1907 Hague Conventions' lineage); Geneva law — the protection branch (the victims: the wounded, the sick, the shipwrecked, the POWs, the civilians — the 1949 Conventions' four). The modern merger: the Additional Protocols of 1977 (the distinction-and-proportionality rules unified); today's IHL is taught-and-applied as one body.
1.2.2 Customary International Humanitarian Law
The custom's role: the rules binding all states without treaties — the ICRC's Customary Study (the 161 rules' catalogue) — the importance for the non-party states (Nepal's own case: the Protocols unratified, the custom applying — U5.7's verified record); the persistent-objector's doctrine; the study's critiques (the identification's method debates).
1.2.3 Martens Clause
The clause's text (from the 1899 preamble, named after Fyodor Martens): where no treaty rule applies, persons remain under the protection of "the principles of humanity and the dictates of public conscience." The functions: the gap-filler (no legal vacuum in war); the interpretation's aid; the debates (the clause as soft minimum vs the customary-law generator — the modern readings).