I would dispute Australia being up there. Do we really have the capabilities to carry out war in another nation? What about initial Air Cover? We could probably defeat Indonesia, because it's so close, but I don't see Australia being able to project enough force to really defeat a country.
I think if we got a small Aircraft carrier we could definitely be up there, until then, I'd be reluctant to accept that.
But the question is pretty open ended, I mean, what does "the worlds most powerful military" mean?
Israel up there? Definitely a player, but they are geared towards kicking ass in the middle east, ie, their immediate neighbours. Could they defeat a far away country, well thats not their military objective.
I think to address the question, we need to define it better than "This is based on technology, equiment, training and warfighting capibility"
Are we saying, "Who can exert military control over their neighbours or region?"
Or "Who can launch long range invasions?"
Or something completely different?
Another one on your list:
Saudi Arabia itself immediately requested US help when Saddam invaded Kuwait in the Gulf war. Also, their oil shipping lanes in the Persian Gulf are protected by US ships. To me, that doesn't sound like a country which is very confident in its own military.
http://en.wikipedia.org/wiki/Image:WorldMilitarySpending.jpg
Here we can see defence budgets, I think this puts together a good list, and a good starting point.