Julian's post is really well worth reading if you want to understand the arguments about the legality of the strike and the increasing irrelevance of the U.N. Charter to the use of force. I think he is absolutely right that the disconnect between legal academics and the international community suggests that non-legal factors are making the U.N. Charter far less relevant to many use of force decisions.In the view of most international lawyers, the US strike on Syria is a crystal-clear violation of the UN Charter. So why doesn’t anybody, except Russia and some international lawyers, seem to care?. . .This gap between the reactions of governments and the reactions of most international-law scholars is striking. If the United States is flouting a law that usefully constrains nations who otherwise might be tempted to go to war, it could be increasing global instability. On the other hand, if the United States acted correctly in its efforts to deter the further use of chemical weapons by using military force, then international lawyers may be revealing themselves to be wedded to an outmoded and formalistic ideas about the international system — to a worldview that overrates the sovereignty of nation-states and underrates the lives of people living within them. This argument is made by dissenters from the international-law “consensus” view, including Yale’s Harold Koh, the former top lawyer in President Obama’s State Department.But there is still another, more hard-nosed, realist take on the foreign reaction to the Syria strikes: that the UN’s rules on when force is permitted don’t meaningfully constrain states’ behavior. Although the Trump administration has not formally endorsed this position, I suspect this view is held by many of its decisonmakers.. . .I am not claiming that international law doesn’t matter; all things being equal, states would prefer to act in concert with their international obligations. But there are many powerful non-legal forces affecting the decisions of states to use or not use military force. Those non-legal forces include questions of global stability, military capability, support from other key and affected states, and domestic political support. Such factors are always going to be more significant drivers of action than the views of international lawyers.
This should not be surprising: the U.N. Charter reflects the experience of World War II and reflects a desire to stop all uses of force in international relationships. The reality of the world today is different, and nations are far less willing to cede the decision to use force to the Permanent Members of the security Council.