Saudi Arabia Alleges “Act of War” — What does it mean?

By Navy Binning

Photo: Great Prophet VII Maneuvers Iran, Creative Common License

Earlier this month, Saudi Arabia charged Iran with an “act of war”.

Saudi Arabia and Iran have been engaged in suppressed aggression and hostility for decades. After Yemen rebels known as Houthis overthrew the government in 2015, Saudi forces began an attack against the Houthi forces to restore the internationally recognized government. Yemen has since been caught in the midst of conflict that has killed over ten thousand civilians. Saudi air strikes have been the leading cause of civilian casualties. Iran has openly expressed its support for the Houthi, but it has never claimed to provide resources or to lead the rebel group.

On November 4th, a missile was fired from Yemen towards Riyadh, the capital of Saudi Arabia, and intercepted over the city’s airport. The Houthi claim the missile attack was retaliation for a Saudi attack that killed twenty-six people. Saudi Arabia and the United States have since accused Iran of providing missiles to Yemen rebels, one of which was used in the attack on Riyadh. Although Saudi Arabia and the United States have previously accused Iran of supporting the Houthis, there has never been direct proof of the allegation.  

Saudi Arabia’s declaration that Iran has engaged in an act of war is a bold one and a particularly foreboding one, following the years of hostility between the two nations. This begs the question —When does an act of aggression amount to an “act of war”?

The US Code defines “act of war” as “any act occurring in the course of (a) declared war; (b) armed conflict, whether or not war has been declared, between two or more nations; or (c) armed conflict between military forces of any origin”.

War can only occur between states. A conflict between a state and a non-state actor, such as a rebel group or terrorist organization, cannot constitute war. The exception is when the non-state actor is sponsored by a state. Saudi Arabia will need to prove that the Houthis were sponsored by Iran in order to properly allege that the missile attack was an act of war by Iran.

The United Nations Charter does not address “act of war”, but it does address the use of force. Article 2(4) requires members to refrain from “the threat or use of force against the territorial integrity or political independence of any state”. The missile attack clearly constitutes a use of force; however, Saudi Arabia must still show that it was a use of force by a member state.

There is no settled definition for “act of war”. The term has evolved to become more political than legal, with many believing that an “act of war” is simply any act that a state uses to justify a declaration of war.
In a statement responding to the attack, Saudi Arabia asserted that “the Kingdom reserves its right to respond to Iran in the appropriate time and manner”. What Saudi Arabia considers to be an appropriate response remains to be seen.