The Truth About Tripwires

A pillar of American grand strategy since 1945 has been the deployment of forces — sometimes smaller and sometimes larger — abroad. A key logic underpinning smaller deployments is that they serve as tripwires: Attacking them is assumed to inevitably trigger broader intervention, deterring aggression. We question this logic. Not only are small tripwire deployments unlikely to prevent an attacker from capturing its objective and establishing a strong defensive position, tripwire-force fatalities may be insufficient to provoke broader...