The complex was surrounded by the same sorts of security barriers and surveillance tech that in other countries might have been used to seal the perimeter of a nuclear submarine base. Not that it was a military target per se, but if some mad saboteur had gotten in there and vandalized a key part of the system, it would have been expensive to repair. If it had happened just before a big storm, and somehow prevented a gate from closing, the resulting damage would have been comparable to a nuclear strike.