NIF being a "military facility" has less to do with laser weapons or power-hungry systems than their type of research indirect drive laser-fusion, being the exact mechanism that takes place in multiple-stage nuclear weapons. The lasers at NIF first generate x-rays, which are then focused on the target to energize the pellet and create fusion.

If you look at the "shot history" of NIF -- the vast majority of their facility's energy is spent on actual DOD weapons research, not fusion research that would be incidentally beneficial to the DOD:

https://lasers.llnl.gov/for-users/nif-target-shot-metrics