What gets me annoyed about this is the hard reality of history: as evidenced by both Pakistan and North Korea, a nation will (if they've a mind to) develop their nuclear capability with a treaty or without one. (Two exceptions being Iraq and Syria, whose plants got bombed by the Israelis in 1981 and 2007).
This decision seems to me a way to cut off one's own nose to spite one's face; it harms harms high tech jobs, and overall national trade/commerce both at home, and among our allies.
The only silver lining I see is that any number of observers have opined that "a new deal" being reworked turns all of this back on. OK, if a "new deal" is worked out, and the orders turned back on, all to the good. But I wonder at the timeline on that.
I am not keen to see the aircraft building industry take a hit, on either side of the pond.
And here's the other thing: the opportunity to increase a variety of low level contacts and influence. For example, you've got simulator / training set ups that can establish the kinds of contacts benefit in a variety of multinational efforts ... OK. Nuff said.