In the wake of the Syrian regime's likely use of chemical weapons last week, the media is focused on UN access to the location of the attack.
This focus is misplaced. Even incontrovertible evidence of the government's use of gas will not create a legal mandate for intervention. Debate should focus instead on how best to help the Syrian people, not on the false promise of international law.
How can it be possible that massacring an entire neighbourhood in its sleep could not be illegal? In international law, governments generally have the right to do as they please unless they accept specific and explicit commitments otherwise. This is known as the Lotus principle, named after the famous Lotus case at the Permanent Court of International Justice in 1927. The government of Syria has not signed any treaty or accepted any legal obligation that outlaws the use of poisonous gas against its own people.
The Chemical Weapons Convention of 1993 is the main inter-state treaty on the subject. This treaty is a model of clarity: Its opening lines state that "each state party to this convention undertakes never under any circumstances … to use chemical weapons". This is as clear as it gets in international law. Unfortunately, Syria has never signed the treaty and is not bound by it.
Syria also has not signed the treaty on the International Criminal Court - the "Rome Statute" - that makes it a war crime to use "asphyxiating, poisonous or other gases, and all analogous liquids, materials or devices" in war. Neither has it signed the Convention Against Torture; the "Ottawa Convention", which bans landmines; the Convention on Cluster Munitions; or many others that attempt to regulate the instruments of warfare. Syria signed but never ratified the Convention on Biological Weapons. These treaties therefore do not apply.
Yet in 1953 Syria did sign the Geneva Conventions and, in 1968, the Geneva Gas Protocol of 1925. These are important commitments. The first establishes general rules for the treatment of civilians in wars, specifying that non-combatants not be subject to murder, torture, rape, or other cruel treatment. The Geneva Gas Protocol prohibits "the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids".
The Syrian government has repeatedly broken the first of these commitments, and if it was responsible for the chemical attacks last week, then it has clearly broken the second as well. But the problem is that, legally, the Gas Protocol regulates only wars between states, not civil wars. It does not govern how a government behaves inside its own territory.
In other words, under its current obligations Syria is forbidden from using gas against its neighbours but not against its own people. The Geneva Conventions are important, but they say nothing about chemical weapons.
To be sure, there are exceptions to the Lotus principle: rules of law that exist without state consent. International law specialists call these "peremptory norms". There are rules against piracy, genocide, slavery, torture and aggression. When Bart Janssens of Medecins Sans Frontiers said this week that the attack "would constitute a violation of international humanitarian law, which absolutely prohibits the use of chemical weapons and biological agents", he was implying that there is a peremptory norm against the use of such weapons. And there is widespread condemnation that usually follows their use, as seen after the tragedy in Halabja, Iraq, in 1988.
But there is little history to back the claim that chemical weapons are universally prohibited. Many states continue to hold enormous stockpiles of chemical weapons, including the US and Russia, which suggests they do not believe they are inherently illegal. In fact, even among the 189 countries that have signed and ratified the Chemical Weapons Convention, only half have made chemical weapons illegal through their domestic laws.
None of this absolves the Syrian regime of its atrocities. The Assad government continues to use any tool at its disposal to remain in power and clearly has no regard for the lives of its citizens. The fact that this latest massacre may not be a violation of international law does not exonerate Assad, should his government be found responsible. At this point, nothing can.
But those who want forceful action against Assad cannot rely on international law as justification. In this sense, the UN inspection team's access to al-Ghouta, where the attack took place, is irrelevant. Those who care about the people of Syria should focus on political measures to escort Assad from power - including changing Russian and Iranian support for the regime, and possibly even the use of force, rather than looking to international law. To do otherwise will only prolong the suffering of the Syrian people.
Ian Hurd is an associate professor of political science at Northwestern University and the author of After Anarchy: Legitimacy and Power in the UN Security Council (Princeton University Press, 2007), and International Organizations: Politics, Law, Practice (Cambridge, University Press, 2nd ed. 2013).
Follow him on Twitter: @Ian_Hurd