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CRT Report
September 25, 2014

The Legal Case for British Military Action Against Islamic State in Iraq and Syria

Hannah Stuart

Amid mounting international agreement on launching air strikes against Islamic State (IS) targets in Iraq and Syria, The Henry Jackson Society’s policy paper The Legal Case for British Military Action Against Islamic State in Iraq and Syria provides a comprehensive analysis of why air strikes in both Iraq and Syria are entirely legitimate under international law.

The report finds that the request for military assistance from the Iraqi government legally allows Britain to take part in attacks not only on Iraqi soil but also – because a victim state’s right to use force is not restricted territorially when the host state is unwilling or unable to repress the relevant terrorist activities – in Syria, from where IS controls its huge territory and coordinated the invasion of Iraq.

The policy paper raises several key legal arguments, including:

  • International law enshrines the principle of collective self-defence at the invitation of a state (Iraq) under armed attack from a non-state actor (IS) as well as individual self-defence to protect British nationals held hostage by IS.
  • British military action in Syria at the request of the Iraqi government would be lawful without Assad’s consent because Syria, the host state, has demonstrated unwillingness to repress the terrorist actions emanating from its territory which continues to threaten Iraq.
  • This interpretation is supported by state practice, notably international responses to the 2001 US-led invasion of Afghanistan to degrade al-Qaeda which also targeted the Taliban; and was reiterated as British policy by the former Attorney General in the House of Lords in April 2004. 

The Legal Case for British Military Action Against Islamic State in Iraq and Syria is available to download here

Hannah Stuart

About Hannah Stuart

Hannah Stuart is a Research Fellow at the Henry Jackson Society and has authored reports on extremism, terrorism and jihadist ideology as well as religious law and the role of religion in the public sphere. Hannah has a strong research record and her work has informed UK government policy. She gave testimony to the UK Home Affairs Select Committee on radicalisation. She has written analysis for the Wall Street Journal, The Times, Foreign Policy, Current Trends in Islamist Ideology, and the Guardian, among others. Hannah has a MA in International Studies and Diplomacy (with Distinction) from the School of Oriental and African Studies, and a BA in English Literature from the University of Bristol.

Full profile  |  See all of Hannah Stuart's work