Just to provide a reference for what you say: to have a "war", one does not need a nation state. And the Geneva conventions on laws of war do apply to armies and militias regardless of whether they are of a recognized nation state. The conventions apply in civil wars, too.
The Daish (IS) fighters are in gross breach of laws of war even though no one recognizes their "state".
The collection of the Geneva conventions is available in many places, here is the site of IRCR:
There used to be a nice, simple presentation of the laws of war at http://avalon.law.yale.edu/ but now you get 500 Internal Server Error for the archives.
However, to be "at war with terrorism" is unfortunately a very difficult position. Definition of terrorism if by necessity quite vague and problematic. (What is "freedom fighter" for one party or at one time may be a "terrorist" for another or at another time).
-- Edit: I see you sourced the ICRC site for conventions yourself.
The Daish (IS) fighters are in gross breach of laws of war even though no one recognizes their "state".
The collection of the Geneva conventions is available in many places, here is the site of IRCR:
https://www.icrc.org/en/war-and-law/treaties-customary-law/g...
There used to be a nice, simple presentation of the laws of war at http://avalon.law.yale.edu/ but now you get 500 Internal Server Error for the archives.
However, to be "at war with terrorism" is unfortunately a very difficult position. Definition of terrorism if by necessity quite vague and problematic. (What is "freedom fighter" for one party or at one time may be a "terrorist" for another or at another time).
-- Edit: I see you sourced the ICRC site for conventions yourself.