April 2018 Strikes on Syrian Chemical-Weapons Facilities Without UN or Congressional Authorisation

What happened

On 7 April 2018 a chemical attack struck Douma, in the eastern suburbs of Damascus. The US government assessed that the Syrian regime had used chlorine and possibly sarin, killing "dozens of innocent men, women, and children" (OLC, citing the US government assessment). The UK put the toll at up to 75 dead and over 500 injured. In the week before the strikes, Russia vetoed a Security Council resolution that would have created an impartial investigative mechanism (UK Government); the US ambassador said Russia had vetoed chemical-weapons resolutions on Syria six times (Al Jazeera).

At about 4 a.m. local time on 14 April, US, British and French forces struck three facilities:

• the Barzeh Research and Development Center near Damascus, which the US said was used for chemical and biological weapons research;
• the Him Shinshar chemical-weapons storage facility near Homs, assessed as the main location of sarin-production equipment;
• a Him Shinshar storage facility and command post.

According to the Pentagon's briefing as cited by OLC, the US fired 105 missiles. Russia's military said at least 103 cruise missiles were fired by the three countries and that Syrian air defences intercepted 71; the Pentagon said none was intercepted. Syrian state media said missiles aimed at Homs "injured three civilians" (Al Jazeera). The US deconflicted the airspace with Russia in advance (OLC).

The legal positions

The United Kingdom published its legal basis the same day: "humanitarian intervention." Its conditions are convincing evidence of extreme humanitarian distress, no practicable alternative to force, and a necessary and proportionate response (UK Government).

The United States, in the sources reviewed, did not publish an international-law justification. On 31 May 2018 the Justice Department's Office of Legal Counsel published a memorandum on domestic authority. It concluded that the President "could lawfully direct airstrikes… because he had reasonably determined that the use of force would be in the national interest and that the anticipated hostilities would not rise to the level of a war in the constitutional sense." It relied on regional stability, deterrence of chemical-weapons use and similar interests. The opinion does not discuss the UN Charter.

Other states: China said "any military action that bypassed the UN Security Council violated the principles and basic norms of international law." Iran called the strikes a "flagrant violation of international law." Russia urged the Security Council to condemn the "aggression." Turkey welcomed the strikes, and Secretary-General António Guterres urged restraint (Al Jazeera).

Legal analysis

Aggression (Rome Statute Art. 8 bis): considered, not met.

1. Use of armed force against another state's sovereignty. Met. These were missile strikes on Syrian government facilities.
2. Inconsistency with the UN Charter. Prima facie met. There was no Security Council authorisation and no self-defence claim. Humanitarian intervention is not a Charter exception, and its standing in customary law is disputed; several states rejected it here.
3. A "manifest" violation by its character, gravity and scale. Not shown. The strikes were limited to three chemical-weapons-related sites over a few hours, caused no reported deaths, and were aimed at deterring the use of a weapon banned under international law. The humanitarian-intervention argument, while contested, makes the illegality less than manifest. The ICC also lacks jurisdiction over aggression by nationals of non-States Parties (Art. 15 bis(5)).

No war crime is suggested: the targets were military-related facilities and no civilian deaths were reported.

Domestic war powers. The OLC test makes congressional authorisation unnecessary whenever the President reasonably anticipates limited hostilities that serve a "national interest." That test has no clear outer limit, and it was written for a precedent-setting strike on a state with which the US was not at war.

Strongest defence argument. The strikes responded to repeated use of chemical weapons, itself a war crime, after the Security Council was blocked by a party's ally, and they were narrowly targeted and caused no reported deaths. That is a serious moral argument and why aggression is not found here. It does not supply a Charter basis, and it does not answer the domestic constitutional concern.

Why this grade

Critical, matching the April 2017 Shayrat strike. The concern is structural: a second unilateral use of force against a state without Charter basis or congressional authorisation, and a published executive-branch legal theory that widened the President's claimed power to start hostilities alone. It is not extreme, because the "manifest" threshold of Article 8 bis is not met at the probable standard. No warCrimeClassification is given, since no international crime is plausibly in play at the Art. 53(1) level.