Recent events in Syria –President Bashar al-Assad’s horrific chemical weapons attack on civilians in Idlib, and the Trump administration’s subsequent missile strikes – have again forced to the fore the debate over the legality of humanitarian intervention in international law. Naturally, we tend to focus on these questions in the context of an immediate catastrophe, or a particular use or threatened use of force. Thus, the legal question of humanitarian intervention is often inextricably bound up with the extent to which any particular military operation is sound policy. That focus may over-emphasize action, and fail to grapple sufficiently with the wide space in which states do not act, or limit policy options based, at least in part, on the constraints imposed by international law. I would like, therefore, to try to separate for a moment the legal question from President Donald Trump’s recent actions, and from our sense of the extent to which he may be able to put forward a responsible strategy in Syria. To be clear, I have little hope that this president is the one who will be able to thread this needle. But, as we are all painfully aware, Syria’s humanitarian disaster is hardly new. For years now, international law has failed in Syria.What is "international law?" There's the classic definition:
The international law question at stake is simply this: May a state or states lawfully use force against another sovereign state for purely humanitarian reasons, without sanction by the UN Security Council? (emphasis added)....
International law, also called public international law or law of nations, the body of legal rules, norms, and standards that apply between sovereign states and other entities that are legally recognized as international actors.Now, I am a simple man, and I always ask this question about any "law" - "How will it be enforced?"
As a result, in many of those cases involving things like "humanitarian intervention" my conclusion has been that the invaded or attacked country/entity seems to be the logical enforcement agent - or the entity to resist having the will of others imposed on it. A weak state which cannot deny access by the forces of "good intentions" is pretty much fair game for the stronger do-gooders of the world, regardless of UN approval or sanction.
Take Syria, please (insert Henny Youngman joke).
Some argue that there is no legal basis for intervention into Syrian domestic matters, no matter how horrific. See The U.S. Has No Legal Basis to Intervene in Syria or Breaking international law in Syria.
Others assert there is such a legal basis, as in HUMANITARIAN INTERVENTION IN SYRIA:THE LEGAL BASIS .
Some suggest that there might be a legal basis, but it hasn't been properly identified, see The ETF and the Legality of U.S. Intervention in Syria under International Law
Now, in setting out the above, I have magically confused issues: humanitarian interventions and those other justifications for fighting in another country against the regime that "rules" that land. If you read the above links you might be able to sort it out, but it misses the point I am trying to make here, which is that regardless of motivation or justification, a more powerful force - whether it be a single nation or a coalition - can violate national sovereignty of a country pretty much at will unless that country (and any allies it has) can defend itself from such violations.
When Iraq invaded Kuwait, Saddam offered rationales, but the U.S. and a coalition refuted those rationales with force. When Russia invaded Crimea or chunks of the Ukraine, it offered rationales (like "protecting ethnic Russians") and the Ukraine itself has fought back, though no alliance has jumped in with troops to help the Ukrainian forces with supporting troops. I'll toss in Libya as an example of "humanitarian intervention" but we all know that went south pretty quickly - see From Responsibility to Protect to Slave Markets, creating a whole new set of issues.
Based on where you sit, you can argue, as the Russians seem to be doing, that the intervention in Syria by non-Syrian and non-Syrian allies in the domestic affairs of Syria is illegal and that Russia and Iran are merely doing what the coalition did in the first Gulf War, protecting a sovereign country from outside forces. I'm not suggesting I agree with that view, but it is out there.
In any event, it would be nice if nations could sit around and peacefully resolve various issues, but the reality is, as Mao noted, "Political power grows out of the barrel of a gun." Substitute "International Law" for "Political power" and you will arrive at a truth. International law is of two parts - that part, like maritime law, that nations agree to for the smooth flow of trade which directly benefits them and the other type, that part which "grows out of the barrel of a gun."
So, call me a cynic, but worrying about the niceties of international law in light of what is happening in the reality of Syria is to completely miss the point. This is about power and, ultimately, international law is only as strong as the ability to enforce it.
UPDATE: See also International Law in Times of Hegemony: Unequal Power and the Shaping of the International Legal Order