Take that scenerio with the Red Cross and a new convention to treat government sponsored criminals as not allowed to attack the Red Cross. It is far less risky to act like they already have that protection and every state should punish a State that violates their existing promises under existing convention than to navigate the situation where a superpower does not ratify the new convention and claims retaliations and shaming are technically violations of their sovereignty.
For a state in the current situation to deny such analogies seems paradoxical to me.. The Internet was not the wild west it was supposed to be for everyone when it comes to their own advantage, but still as dangerous as the wild west due in large part to criminals that are connected to sovereign States and largely shielded using rights to war logic.
The problem is that it’s wildly implausible that there is such an emerging customary norm. And there really is no way to claim with a straight face that this sort of thing falls under the terms of the GCs. And the problem with making aggressive claims about customary norms is that IHL really only does work if people agree to make it work. The worst thing that could happen is to have countries not even pay IHL lip service.
But this all gets to the really, really hard but fundamental question of international law: enforcement. I was piqued by you originally using the term “legislation” just because the way we think about legislation, there is usually an executive to enforce it. That’s part of what makes it “law.” But there is no such thing in international law, and given how overwhelmingly powerful states continue to be, there won’t be in my lifetime. I love the idea of international law, but this is what makes it so slippery and difficult and frustrating.