What passport?

When I was in the US military a set of orders listing countries allowed
to
travel in (and that had agreement with the US) was all that was needed
to travel.

One other thing to understand is that US citizens can go to Canada or
Mexico without a passport so travel throughout North America has
few requirements. After 9/11 I don't know if this is going to
change.

I suspect that in time all of the EU may let passport requirements ease
for inter EU travel of EU citizens

Scott Siebold.