NIF's nuclear weapons research was in support of maintaining the current arsenal of nuclear weapons. Most notably, it helps solve the question of how to ensure

NIF's nuclear weapons research was in support of maintaining the current arsenal of nuclear weapons. Most notably, it helps solve the question of how to ensure current stockpiles are reliable without actually detonating a nuke (since that's a huge no-no). It also kept a generation of nuclear physicists and engineers in employment, and also providing a method by which to test future weapons designs. So really, the answer is, it doesn't matter how many nukes we have right now, NIF was created (in part) to ensure that the capability to blow up the world could be maintained. As depressing as it is, it's pretty much how it goes with nearly all defense technology spin offs. Why the hell did we spend all that time working on rockets that purposefully crashed back onto the Earth (on top of people!) instead of doing something like getting communications satellites up, or getting to the moon.