Don't forget our friends the Saudi's. You are correct. I know of no gurrilla movement that was totally indigenous, that was totally devoid of outside support from countries who used the gurrillas as their proxys.
Iraq is bordered by several countries who's interests are, or have been known to have been, very hostile to ours. The continuing support of these countries is responsible for the deaths of our soldiers. If Syria, Jordan, Turkey, Saudi A., Iran, and Kuwait locked down their borders, the Iraqi "resistance" would rapidly dry up. I wouldn't put the Russians out of reach either. After all, these guys generally carry AK's, not M16s, and I don't know of many AK factories in the Middle East. Whether it's material aid, money, or intelligence information, I'm sure some or all of these countries are playing "realpolitik" at the expense of our servicemen and women.
I hope Bush acts to shut down the outside support. He hasn't been all that "PC" about prosecuting the war thus far, but word I've heard is that the White House want's to cool things down as much as possible between now and election day. They don't want any new wars, or expanded conflicts. But then again, we didn't want one on 9/11 either.
SFS