We say that in Greek the word xenos has 2 meanings, foreigner and guest. Wrong. It was one word with one meaning. Our modern languages are broken: the words multiply but their meanings shrink. Xenos was someone who comes from outside and needs to be washed, fed, and showered with gifts, because he could be a messanger of good news or even a god.
Nowadays we don't mind a guest for dinner (guest after all comes from sanskrit ghas-i, meal), but he/she is normally a friend, not a stranger, who could be rather a fiend.
Ancient Greece was not a political entity and its centre constantly shifted over the sea. Small communities were scattered between the islands of the Aegean, the costs of Greece and Asia Minor. His supreme God was Zeus, the god of metamorphosis and protector of the xenoi. A foreigner is in fact someone who might need to change his apperance in order to travel safely. In Homer, Odysseus is the xenos, often in disguise. When he lands on unknown shores, he wonders whether it will be a civilised place, where people know the customs of xenia and do not make difference between a foreigner and a guest, or he will meet barbarians, who will treat him with hostility.
The time of change and metamorphosis has gone. Rigid boundaries have been erected between countries, meanings, identies. The more the country is civilized (which means only technologically advanced) the more his officer at the borders will look at us with suspicion. We can have the impression that we are freer to travel, but we lost our right to be xenos.