Yes, and now you can see another "perspective". /QUOTE] kevinsmap
I'm not sure that is really true - that at any time, ancient or modern, 'visitors need an invitation'. If that were true no one ever in the history of modern humans would be welcome to travel anywhere. Especially people who overland or long term travel. Normally when someone enters an area inhabited by strangers, the rules of hospitality suggest the locals invite the visitor for time spent together to get to know them a bit. And thus each discover they are harmless to one another. Sometimes the visitor might do something to help that process along...
Precisely, and you have answered your own speculation; an invitation must granted before or upon arrival at the borders of another peoples home(land). Certainly it may be offered (as you suggest), but if it is not... and if it is not requested or even seen to be needed... then that is the very definition of "Invasion". The result of not requesting hospitality, that crucial invitation to stay, is warfare.
(Edit added: A point you make is well taken, that when we travel (overloading included) we cross borders with a reasonable expectation that our visit will be granted and welcome. But we all
must "play by the rules", do we not? Is it not very dangerous to do otherwise? We arrive with documents requesting the grant of passage... exactly such "hospitality" as I describe... and requesting a formal grant of invitation to visit - that stamp. We all know that there are many circumstances in which we will be turned away. The Expedition Portal is an invaluable resource to learn these rules, both official... and more ad-hoc, shall we call it.)
These realities have never prevented people from traveling, or stopped migration. Topical again today, true?