Makes perfect sense to me. Any non-retaliatory nuclear strike would be met with extreme international censure, and possible counter-strikes from other nuclear powers. It's hard to imagine a scenario where the US would ever stand to gain more than it would lose by doing so.
As for defending itself against nuclear powers, the current US arsenal has been more than capable of deterring any nuclear threat for many decades now, and there's no sign that it will need more or better nuclear weapons in the foreseeable future.
Despite the policy making all kinds of sense, no doubt the Pentagon fought hard against it. They hate to take anything off the table when it comes to defense, no matter how distasteful the technology is to the American public or the world community.
"The worst part about these reviews is they are [subjective]--and their scores often depend on how drunk you got the media at a Street Fighter event." — Mona Hamilton, Capcom Senior VP of Marketing
*Image indefinitely borrowed from BrainBoxLtd without his consent.
