From somebody who is on 4 hour notice for international travel, American MONEY is always welcome, Americans themselves not so much.
It's always good to have a trusted translator who tells you what people are actually saying about you and I try to avoid anything on my person which identifies me as American.
I have no notice. Usually, I wake up in a foreign land with mere seconds to figure out the parameters of my mission before my brief disintegrates. I'm lucky if they've given me a handful of local currency and a new fangled weapon of some type.