The SM-3 Block IIA Interceptor

A New Arms Control Challenge

Laura Grego

Published Aug 29, 2019


Planned upgrades to the Aegis Ballistic Missile Defense system are likely to have serious effects on the world’s strategic nuclear balance. While currently a regional defense, new interceptors could make the system theoretically capable of engaging intercontinental-range nuclear missiles. The system’s actual strategic defensive capability is severely limited by its vulnerability to decoys and other countermeasures; however, the system’s dramatic expansion will still have a devastating effect on our prospects for extending existing nuclear arms control agreements and negotiating those that might follow. It will also likely motivate Russia and China to diversify and grow their nuclear weapons arsenals.



Grego, Laura. 2019. The SM-3 Block IIA Interceptor: A New Arms Control Challenge. Cambridge, MA: Union of Concerned Scientists.

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