This topic had been mentioned in various context already, in discussions about US `People Militia` as well in popular media (movies - `Red Dawn`, `Invasion USA`, TV show `Jericho`, PC games `World in Conflict` etc.).

So the question - is there a REAL power/enemy who either wanted and could invade USA? The ICBM attack or major terror acts won't be enough, the direct military invasion is considered.

My opinion is - no, there is not. Nobody posses such resources to invade ground of USA.

I believe that anything is possible. Look at 9/11. Did anybody really think that someone would try to use planes as weapons? I think that we should be ready for anything.

I can't see USA being "invaded" in the foreseeable future according to the true sense of the word. I think that the countries that perhaps have the manpower lack a credible logistic ability.

The only nations that possess both the technology and manpower to invade the USA (India, China) do not have anything like the logistical requirements. Until Star Trek style transporters are invented and become commonplace nor will they have either.

I think I can safely say that the USA is pretty much immune to a military invasion at the present time and for the foreseeable future.

Since the advent of nuclear weapons those countries that possess them and have reasonably advanced means of delivering them are largely immune to a conventional invasion. WMD or not, if it was seriously thought that Saddam had a nuclear weapons capability that could have been delivered with the adapted longer range Scuds, I doubt if Iraq would have been invaded in view of what could happen to Kuwait city, Tel Aviv and other middle eastern cities. That is why the US are so eager to avoid Iran developing them.

The US and other Western countries can only be 'invaded' by terrorism since it is difficult for advanced countries to retaliate at a diversified but determined enemy. I suspect the UK with its pro US foreign policy, cosmopolitan population, and lack of patriotism amongst the ethnic groups, is an obvious target.

The west will come under attack commercially over the long run as other countries particularly from SE Asia will be prepared to outwork and possibly out-think them. Empires rise and fall.

I feel that there is little to no chance of a military invasion of America in the near future. Like many other people i feel that there will be constance threat of a terrorist attack of different magnitudes for the foreseeable future

Any country who attemps to invade the US should attack Japan first, and freeze our electronics and steel.

We can no longer mobilize like we did in WWII. America does not have the industrial capacity.

full scale open warfare.. never happen....

illegal immigration.

Armed people. Not gonna happen.