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

The term collective self-defense is not defined in the UN Charter. Customary
international law and the practice of states spell out the conditions necessary to exercise lawful
collective self-defense. All the conditions for the exercise of legitimate individual self-defense,
as described in chapter 4, are requirements for collective self-defense.
Some scholars argue that States must satisfy an additional condition if collective selfdefense
is to be legitimate. They imply that an individual and collective action differ in an
essential way by asking: What is the unique condition that authorizes a third party to intervene in
a dispute in support of another state that is the object of an actual or imminent armed attack?
Three schools of thought have emerged on this point. The first holds that a state has no
legal right of collective self-defense separate from individual self-defense. The late Hans Kelsen,
former professor of law at the University of California at Berkeley, is the chief proponent of this
view. He asserts that self-defense “is a right of the attacked or threatened… state, and no other.” 8
If several states are acting in collective self-defense, then for them to do so each must be acting
in its own individual self-defense. States unable to claim in their own right to be acting in their
individual self-defense—although they may have an alliance relationship with the victim state or
a strong national interest in the matter—cannot act in support of another state; collective selfdefense
can never be more than the sum of states acting in their individual self-defense. Julius
Stone, Australian jurisprudent on the law of force, summed up this position in these words:
“Under general international law, a State has no right of self-defense in respect of an armed
attack upon a third State. “ 9
A second school of thought, whose chief spokesman is D. W. Bowett, holds that “the
right of self-defence is available only to a state which defends its own substantive rights.” 10 This
school is less restrictive than the Kelsen school but it is not without strict limitations. Although
Bowett does not believe that a state must be able to assert individual self-defense to participate in
a collective self-defense action, he does believe that a close nexus must exist between the
assisting and victimized state. He refers to this relationship as an interdependence of the
securities of the states.
Bowett believes that a preexisting collective self-defense treaty arrangement is a
prerequisite, but—and this is a critically important but—he finds that simply concluding a
collective self-defense treaty will not suffice. 11 Rather, the interests of the attacked state must be
“so intrinsically bound up with the territorial integrity and political independence of another
State that the defence by the latter State of the former is truly ‘self-defence.” 12
Bowett has identified three relevant factors in making this determination: geographical,
political, and strategic-economic proximity. 13 These factors are weighed to answer the only
important question: “Whether an attack upon one state in fact threatens the security of the
other.’’ 14 If this test cannot be satisfied, then collective self-defense is illegitimate.’ 15
The Bowett school believes that collective self-defense must be interpreted narrowly,
otherwise the Charter system would be jeopardized. He writes,