In Japan and South Korea there is deepening concern over the reliability of long-time American security guarantees – whether the U.S. will come to their aid in the event of a war. This has been turbo-charged by Donald Trump’s tough treatment of traditional U.S. allies, which has some in Tokyo and Seoul calling for a reassessment of their non-nuclear policies.
I can’t blame them for wanting to do it. Same with a whole lot of other countries right now.
I’d also like to point out that this will necessitate a new round of nuclear weapons tests. We’re giving up on a hard won success:
https://en.wikipedia.org/wiki/Low-background_steel#Present_day