Public International Law is a system of law
IHL and international criminal law criminal law defines international crimes and punishment
for them (genocide, crimes against humanity, crimes against peace, war crimes). IHL overlaps
with this because war crimes are grave breaches of IHL.
Practical People will not fight. Maintaining the IHL means maintaining discipline. Economical
(weapons are expensive).
MOVIE:
WW I poisonous gas. Rights of prisoners not guaranteed
Fulfilling of IHL is a legal and practical recuirement. In Pakistan, they didn't and a lot of civilians
were left without homes etc. americans in Vietnam also make similar mistakes (beat a prisoner,
treat civilians harshly). Incident were there was a suspicion that there is a headquarter in a village,
there wasn't and the americans still killed most of the people and destroyed the village
War criminalrs punished by the state itself, international organizations only if the state doesn't
want to.
Legal order is not a defence