Alex WellersteinVerified account

1. The absolute hardest part about building a nuke is getting fissile material, not "secrets" or information. 2. Nobody who studies nuke issues (and doesn't have a contract with the Pentagon) has any strong faith that ballistic missile defense would work in a real-world crisis.https://twitter.com/Mantia/status/1013559718759956481 …

1. There are many ways to fake them out, 2. Existing systems only show partial success under idealized conditions, 3. Prob. of failure so high, and consequences associated with failure high, that confidence is not at all warranted.

To put it another way: If it comes down to our BMD systems needing to work to avert catastrophe, then we're really in a bad place. That doesn't mean they shouldn't work on BMD (though there are other reasons why that might be an issue, like destabilization w/Russia), but

it does mean that they should not be used as a strong "crutch" in our discussions about deterrence, etc., or give policymakers (or citizens) the confidence to escalate situations.

I worry very much when I hear US officials declare how well BMD "works" and use that as essentially an argument for, say, preemptive strikes. Even a BMD supporter should not be eager to test if BMD works in the real world.