I didn't say stop foreign trade or not protect ourselves. Read what is there.
Tigger, if a nation attacks us then we go in, destroy them, then leave. No rebuilding their country afterwards. That is like rewarding our enemies for attacking us in the first place.
Walsh, we should trade with other countries, and bolster the economies of our trade partners as long as it benefits us. However that does not mean we should act irresponsibly by making excuses to invade other countries. Iraq was no threat to the US, nor any US citizen on US soil. Saddam had no WMDs. Saddam had no connection to Al Qaeda. We invaded on false pretenses and thusly acted irresponsibly and American lives have been lost and wasted.