This is the kind of thinking that gets you in a lot of trouble. People, all over the world, are more or less the same on many basic issues. One of them is respect. People like to get it.
And this kind of bulloney makes me laugh and weep at the same time.
Let's see what's wrong with it all. First off, you can't ignore other countries. That's simply not possible. 'fortress america' won't survive because it couldn't possibly provide itself with enough energy (read: oil). Even if you manage total self-reliance, there is that simple thing called international trade. That would where you gain and the other party gains too, and you would be missing out on it. That's rather painful in the economic sense. I don't have the values here, but I'm sure the net international trade gain for the United States is astronomical. Then there's the multitrillion debt; shutting down international affairs while you still owe a lot of countries money, well, what do we have to do then? Call America the land of the criminal and arrogant, or invade to get it back?
Then there's also the issue of freedom: You want to see Paris someday? Tokyo? Bummer. You go introvert, you are bound to get some countries that simply won't accept passports from the USA. But it doesn't stop there, in order to effectively implement Fortress America, the USA can't allow it's own citizens to cross the border; they could be mentally influenced, killed, etcetera outside. You have to completely close your borders to everything. In fact, you'd have to include internet connections to the outside of the united states, because people can be mentally influenced that way.
You are willfully sticking a berlin wall around your country? You have family in europe? Aw, shucks, you can never see or speak to them again. ever. This is silly.
Then there's this pax americana. If fortress america is silly, this would be somewhere between insane and ludicrous. What exactly do you think will happen in such circumstances?
The basic premise of empire america is that you go in, 'give aid to countries', forcibly take over government. You can be as nice as you like, you can give as much aid as you want, but you're taking too much respect. Forcibly taking over anything gets you hate, and lots of it. Imagine that the European Union jointly decide that The USA is being so braindead in their foreign policy that we'll come over and force the USA to set up a new government system. It'll never happen, but imagine. We wouldn't go and kill anything, wouldn't take any land, would in fact invest funding, and be generally nice. Some will fight for the right to have braindead foreign policy, and we'd kill them. Some others die (Acceptable Collateral Damage). I'd bet pretty much every american would feel attacked. Most would begin hating europeans (or at least strongly dislike) and then there are the minority nutcases that get silly ideas. Involving planes and big buildings or similar terrorist attacks. Not ratifyable by any means, but it sounds plausible, doesn't it?
If you are now thinking that it would be dead-wrong for europeans do that because america is your country and the responsibility of your countrymen, you'd be right. You can apply that to every country you'd want to include in your empire by the way.
If you are now thinking that such an invasion would be silly because the american way is freedom, democratic, blabla, the way countries are meant to be run, you've just put your finger on why a lot of foreign nationals dislike americans. Your system works for you. great. Excellent, in fact. A version which is a bit more exteme on the freedom works for us (that would be the Netherlands and most other european countries). That's nice too.
Helping somebody against his will under the oft heard excuse that 'it's for his own good' is directly opposed to personal freedom. There's a good quote from an american about this but I can't find it right now. Applying it to nations is just as bad. It doesn't work that way. let me quote a part of the article:
>..That means we would have to make people want to be part of it. So we have to
>invade their countries and build up their infrastructure...
Right. em? We want you to like us, which is why we are here. We kill a few, overthrow your government, and force our way on you. Our way is good, see. Now, adore us!
This kind of thinking is what people mean when they say The USA might want to look into their foreign policy and Well, they are partly responsible for provoking it.
Learn the lessons. There's no way you can safe up your country forcibly, either by draconian internal security (hello Police States of America), or by conquest. The easiest way to reach the goal of not letting this happen again is by becoming a bit less arrogant when dealing with other countries. Entering trigger-happy is one thing (sometimes called for, ie: WW2), but you have to respect the culture and the lives of the people that you are messing with.
"is a signature" is a signature.