I would hope the US military isn't as loose to act as its president on Twitter. For the defense industry at least, war is a business, the contracts need to be in place and everything has to be done to the 1000 page spec to a T. Indiscriminate destruction is relatively cheap, but not conducive to a long-term business strategy. The US will act when there is a scheme in place profitable enough to make lobby congress worth the cost expenditure.

I think it's completely possible a missile could be intercepted over the pacific, under strict confidentiality, and no civilian organization will know the better. Paying off a few fishermen is cheap compared to messing up the scheme.