People who ought to know better are saying that the USAF's planned Next Generation Bomber will take longer to develop if it has a nuclear mission.
Pardon me, but this makes no sense whatsoever.
Integrating a bucket of instant sunshine (as the RAF referred to its nuclear weapons) on a bomber is not that difficult. Free-fall nuclear weapons developed since the late 1950s have been about the same size and shape as a 2,000-pound conventional bomb. Nuclear weapons do need special safing, arming and securing mechanisms, but dozens of different aircraft types, ranging in size down to the A-4 Skyhawk and below, have been fitted with them over the decades. Installing the weapon certainly is not the long pole in the tent when it comes to development.
Full-up "rad-hardening" might be a different matter, affecting a lot of onboard systems - for instance, optical signals might replace a lot of wiring. But whether you'd need the sort of hardening specified for Cold War bombers, designed to operate with both bombs and nuclear SAM warheads going off left, right and center, is very debatable. (One of the best B-2 stories is that a vast amount of money was spent on a special rad-hardened communications system - but by the time the bomber was ready, the rest of the system had been cancelled so it had no one to talk to.)
Once again, the main reason anyone wants to delay a start on NGB is to give Boeing and Lockheed Martin a chance to catch up with Northrop Grumman - since a great deal of evidence suggests that the latter is building a secret X-plane demonstrator for NGB.
If the secret NGB is as promising as one would hope it is, here's a suggestion for the USAF: bring it out of the black world as soon and as dramatically as possible, presenting it as an aircraft that generates as many options for the US as it creates problems for its adversaries.
That, by the way, is also a neat summary of one of the most successful bombers in service today, the Tu-22M2/3 Backfire. It wasn't as sophisticated as the USAF's B-1 or the later Tu-160, having been developed cheaply and almost subversively, but its range, payload and survivability presented huge headaches for NATO and the US Navy.