The US would be one of my last choices. Of course I'm not an American but the statistics speak for themselves. Insane crime rates, murder rates, everyone has a gun, poverty, unsupportive system, abominable health care... You gotta have a lot of luck to live among the privileged. True about the military thing though - I don't see USA ever falling to foreign invasion.
Taking over the US wouldnt be too hard.
*wait until poverty gets bad enough and causes even more violence*
*send in your army while Americans are killing eachother*
I wouldnt consider America safe at all. Too easy to get guns, I much prefer restricting guns so not every drunken [censored] has one.
Edit: Australia seriously ?
Sydney funnel webs alone, make that place hell on earth. Didnt it also manage to be half flooded, while the other half was on fire recently ?
I wouldnt even visit Australia on holiday, way to many things that want me dead, and usually have the poison to do the job. (in horribley painful ways).