I have some more thoughts on “left of launch” cyber-espionage against the North Korean ballistic missile program up at the Diplomat:
To be sure, The New York Times could not confirm the impact of U.S. sabotage efforts; building and testing ballistic missiles is tricky business, and accidents happen whether the U.S. has its thumb on the scales or no. Nevertheless, the use of cyber-espionage to disrupt the development of foreign ballistic missile systems, in particular, raises some difficult questions about nuclear deterrence…
…For example, several years ago the Russian military experienced a series of failed tests of its Bulava submarine launched ballistic missile. Every indication suggests that these failures happened for domestic reasons; the Russian aerospace industry struggled to find its footing in the wake of the Cold War, and the serial Bulava failures were an understandable, if embarrassing, part of the process of reconstitution. In retrospect, however, some Russian spies and engineers probably have cause to wonder whether the missile failures had an external cause. The idea that U.S. cyber-espionage disrupted Russian missile development is simultaneously far-fetched and evidence-free, but is certainly more credible today than it was last week.
See also this excellent Matthew Waxman post at Lawfare:
First, did the U.S. government regard electronic sabotage of ballistic missile tests as an act of “force” or an “armed attack”? The multi-factor approach to cyber-attacks as “force”/“armed attack” leaves a lot of room to argue this either way. I assume that the U.S. government wants to keep open some legal flexibility to conduct this type of cyber-operation, but I also suspect that it would it would regard as quite reasonable a determination that a disabling cyber-attack against U.S. missile systems constituted an armed attack—and therefore justified self-defensive force. The Times story notes that this cyber-operation has echoes of Stuxnet attacks that, as has been widely reported, physically wrecked Iranian nuclear centrifuges, and any internal legal analysis may be similar, though it is unclear exactly what effects the North Korea attacks had on missile systems that may ultimately have contributed to test failures.