Legitimate use of military force against state-sponsored - Air University

Strictly speaking, the right of individual self-defense is a privilege. 7 According to Max
Sorensen, professor of international law at Aarhus University in Denmark, “international law
recognizes that certain acts, which would ordinarily be unlawful, are, when committed in selfdefense,
legitimate and do not give rise to responsibility.” 8 Thus, in principle, articles 2(4) and
2(7) establish the prima facie illegality of use or threatened use of force and intervention by
states while article 51 affirms the inherent right of self-defense and grants to states an excuse or
limited privilege justifying what would otherwise be illegal coercion. If a self-defense action is
proper, then a state is relieved from responsibility.
Self-defense is distinguishable from self-help and from the concept of aggression.
Although self-defense is a form of self-help, self-help is broader than self-defense. Self-help is
any and every means by which states pursue their rights and interests; some are legally
permissible and some are not. Self-defense is a specific form of self-help, that is, an “affirmation
of rights illegally and forcibly denied.” 9 Self-help is only legitimate to the extent that the specific
form of self-help, such as self-defense, is legal.
Aggression is different from, and irrelevant to, the concept of self-defense. Aggression
occurs whenever a state’s actions threaten another state in specific ways. Aggression is not
limited to force. Aggression can occur in other forms such as economic aggression. Aggression
is one of the preconditions for action under article 39 of the Charter for implementation of
enforcement actions under chapter VIII. Aggression is not a precondition for action under
chapter VII of the Charter, including self-defense in article 51. Article 51 focuses on armed
attack and not aggression. As summarized by D. W. Bowett, “in considering whether a situation
affords a state the right of self-defence the only relevant concept is that of self-defence; the
concept of aggression as it has been elaborated during the course of the last forty years has an
entirely different purpose.” 10
It is certainly possible, however, that state misconduct can amount to both an armed
attack and aggression. They are not mutually exclusive. The United States has viewed statesponsored
international terrorist acts as armed attacks justifying self-defense—as was the case in
the 1986 Libyan raid—or as aggression, as noted by Secretary of State George Shultz:
A state which supports terrorists or subversive attacks against another state, or
which supports or encourages terrorist planning and other activities within its own
territory, is responsible for such attacks. Such conduct can amount to an ongoing
armed aggression against the other state under international law. 11
If the attacks conducted by terrorists and their state sponsors are armed attacks, then self-defense
in article 51 is the option to consider. If, on the other hand, an act of aggression under article 39
is evident, then the focus is on the enforcement measures under chapter VIII of the Charter.