The original question mentioned that one airport has been blown-up and
another is unusable for some reason. If this kind of attack was going
on, if I were running the GPS network, I'd turn it off.

Depending on the damage that has been done, VORs may well be dead.

And since the original poster appears to me to be from Australia, they
probably use more ADF equipment than we do here in the USofA. But my
original comments were geared more toward the mentality of the
HSA/TSA/FBI/FAA and what they would decide to do.
Later,
Steve.T
PP ASEL/Instrument