Over at Balkinization, Brian Tamanaha reprints the American Society of International Law's recent resolution about international law and the Iraq war. Tamanaha is correctly that the resolution merely restates what everyone knows about international law, so he believe ASIL is just making a statement about the Bush administration's conduct in starting and conducting the war.
Now of course almost no one disagrees that international "law" governs the use of force and that torture or even cruel, inhuman, or degrading treatment is a violation of international law. It's also quite possible that the Bush administration has violated international law. But the administration's response to such charges is not that international law is irrelevant, but that its conduct does not fall outside the bounds of the law.
For example, the administration does not deny that the Geneva Conventions governs "[c]onduct of armed conflict and occupation." It argues that these conventions do not apply to prisoners who do qualify for its protection according to the explicit requirements laid out by the conventions themselves.
It also does not deny that "Resort to armed force is governed by the Charter of the United Nations and other international law (jus ad bellum)." Rather it argues that the myriad binding Security Council resolutions against Iraq justify the use of force to enforce them under Article 43.
Perhaps groups that criticize the administration would do better if they actually explained what they thought the administration did wrong, rather than pretending it's obvious (or as Dovbear would say "everyone knows [they broke the law]")