1/8 I'm thrilled to publish this new report authored by me and @ArmsControlWonk for @NTI_WMD examining global missile defense tests and operational uses.

2/8 We tracked down every instance we could find of a missile defense engagement involving an attempt to intercept a missile with another missile. From 1960-2019, we found 365 total engagement attempts (221 tests and 144 combat engagements) conducted by 9 different countries.

3/8 While some systems showed impressive results in tests, this did not clearly translate to verifiable successes on the battlefield. In the 30 years since missile defense systems were first used in war, we were unable to identify a clear, slam dunk battlefield success.

4/8 In the aftermath of attempted combat intercepts, most states issue broad statements of success and rarely release details allowing for independent analysis. In a few cases where additional info was available, evidence pointed more towards failure than success.

5/8 This doesn't mean there hasn't been one, there are often strong incentives to conceal the true effectiveness of missile defense systems during war and some systems may be quite effective under narrow circumstances.

6/8 However, it's not clear if policy makers understand that. These systems may be spreading so rapidly in part because these same policy makers want to find ways to reassure public anxieties.

7/8 Unfortunately, adversaries generally have to take missile defense systems seriously one way or another, and instead are working to develop newer systems and tactics as a counter. Read the full report here: https://www.nti.org/analysis/articles/global-missile-defense-race-strong-test-records-and-poor-operational-performance/

8/8 And check out the entire data set here: https://www.nti.org/analysis/articles/cns-global-missile-defense-engagement-database/