On the Necessity of Pre‐emption

The attacks of September 11, 2001 led President Bush to declare a 'war' on terrorism. Terrorists are capable of inflicting grave damage, and are not susceptible to the deterrent pressures felt by states. Pre-emption and prevention of attacks have become part of the US national security strategy to deal with this danger. International lawyers claim that pre-emption must be limited to actions in response to an attack that is imminent and unavoidable by any other means. This paper examines the background of the requirement that pre-emption is restricted to imminent attacks, and argues that the narrow standard properly applies only when a potential victim state can rely on the police powers of the state from which a prospective attack is anticipated. A more flexible standard for determining necessity is appropriate for situations in which the state from which attacks are anticipated is either unwilling or unable to prevent the attacks, or may even be responsible for them. The situation posed by Al Qaeda, operating from Afghanistan, was one in which the Taliban explicitly refused to prevent attacks on the US by that terrorist organization. The question of the applicability of the rule regarding necessity to Saddam Hussein's Iraq is more complicated, but a strong case can be made for the necessity of pre-emptive action.