The legal basis for air strikes against Syrian government targets

Richard Ware

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The legal basis for air strikes against Syrian government targets (273 KB , PDF)

Download ‘The legal basis for air strikes against Syrian government targets’ report (273 KB , PDF)

Government legal position

The Government has published a summary of the legal advice on which it based the decision to participate with the US and France in air strikes on Syrian government targets on 14 April.

International law and the use of force

There is a general prohibition in international law on the use of force or threat of force directed at other states. This is stated most explicitly in the Charter of the United Nations which is universally recognised as a primary source of international law because the great majority of nations have signed or acceded to it.

The United Nations Charter

The UN Charter envisages that the Security Council will act to maintain international peace and that the preferred source of legal base for any necessary military action to this end will be a Resolution of the Security Council. Failing this, the Charter recognises an inherent right to self-defence which nations may exercise individually or collectively pending action by the Security Action. Because nations are entitled to take part in collective defence, military action may also be legally justified where a state has requested assistance from another country (the basis used to justify Russian intervention in Syria).

Doctrine of humanitarian intervention

The UK legal advice cites a fourth potential legal basis, which is the doctrine of humanitarian intervention founded in customary international law. Customary international law is based on the practice of nations and continues to exist alongside the UN Charter. Where it finds suitable evidence the International Court of Justice may apply appropriate customary law.

Humanitarian intervention based on customary law is described as an exceptional measure subject to strict conditions which the Government believes have been met in the case of Syria and chemical weapons. Humanitarian intervention was also used in 1999 to justify NATO action to protect civilians in Kosovo.

The use of the doctrine is controversial, however and legal opinion is divided.