What if Al Qaeda
deemed Pine Gap a threat to their operations and send a team through
the fence.

Here's a little from a piece posted on Webdiary by Brian Law last Decemberr:

[extract] 

Again we climbed through and realised all the power of the greatest
empire in history could not stop two untrained, unfunded, unarmed
Christian pacifists from entering one of their most important and
secure bases - even after we had told them we were coming.

I looked around at the huge white domes and radar dishes around us.
It was obviously not possible to climb onto one of the white domes as I
had sometimes fantasized. Adele headed for a tower next to a building
and climbed on to the roof. I followed.

Once on the roof we placed photos, leaflets, and other information
on the roof and gave thanks to God. Shortly after we watched as a
security guard on a bicycle road around. We still had not been seen.
But the guard then rode around to the back of the building and must
have noticed the banner on the fence. Meanwhile Adele and I took photos
of one another with a huge white dome behind us. The security guard
came back in sight and quickly climbed a tower holding a radar dish
directly in front of us. Amazingly (although by this time nothing would
surprise us), he must have looked around for a minute before seeing us.
I waved, and he scrambled back down.

Within a minute there were a number of Federal security guards and police assembled below us.

 Maybe there was scanning equipment in place that would've detected
more threatening articles than crucifixes and pamphlets, maybe not.  
Maybe Bryan and crew proved how easily an Australian/American
modern-day version of Pearl Harbour could come to pass?   Would the US place more troops in Australia to protect its Sentinel In The War On Terror (or somesuch phrase) ?  Would it perhaps feel obliged to use the US/Australian Joint Facilites to demonstrate it's new planned "Lily Pad" capability- the ability to mobilise its troops to hotspots?

The above paragraph is my own pure conjecture, as is the one below.

What if Downer's stories of Australia being within Korean missile range
actually turned out to be true? If so then the Axis of Evil's foremost
concern might be knocking out the JORN detection system. This might be
achievable by knocking out dishes, but much more effective would be
disabling its headquarters in Adelaide.

Worse, what if the above two ideas were carried out in concert?  A combined missile/terrorist strategy would no doubt shock the world.

It doesn't matter whether
or not I believe either possibility or their combination likely. I conjecture that as a set
of calculations were carried out on the proposed national nuclear dump
pertaining to possible environmental damage due to a nuclear
containment breach from a missile attack(the figures were worked out
for ARPANSA by Halliburton), then such hypotheses as I have raised
above will have been well and truly considered by both US and
Australian military, and contingency plans laid.

Its becoming like a game of potentially bloody global chess as we attempt to anticipate our leaders' next moves.