Nice to see you are also a Nuclear weapons expert. However having been a security officer for the Atomic Energy Commission on the atomic bomb test site  in 1968 at Amchitka Island with a top security clearance,  I had to deal with the bomb experts from Nevada. 68 and 69 were the last actual testing of US nuclear warheads. Our island was repeatedly circled by Russian spy ships and overflown by Russian  surveillance aircraft trying to steal our Nuclear secrets. Upgrading our old weapons in the face of Russia who is on a new aggression mode in Europe and the Middle East and violated all agreements on new missile development and warhead capabilities , I humbly say you are wrong.