Japan has the capability to take out the sites themselves. They have quietly acquired air refueling tankers, modified their fighters to air refuel (air refuel doors on F15s were welded shut but all piping was in place) and they have been practicing with US forces for years.
They have four KC-767s and know how to use them by now. They can reach just about anywhere in NK.
All their “self” defense forces have offensive capability.