Respect for State Sovereignty: Primacy of Intervention by Invitation over the Right to Self-Defence

The “Islamic State” (IS),1 a terrorist organisation acting independently of
any State,2 controlled large portions of territory in Iraq and Syria.3 In June
2014 Iraq asked for international assistance in its fight against the IS on the
Iraqi territory.4 Then, in September 2014, Iraq asked the United States (US)
and its allies to help it in defending itself against the IS in Syria as well.5
However, Iraq could not invite States for intervention outside its territory.
The only legal ground Iraq could refer to here was the right to collective
self-defence of that State in reaction to armed attacks by the IS.