Lots of theories but no clear cut answers. I think it’s the ease of travel planning thanks to the internet and people’s desire to connect with others in the world thanks to social media sites like Facebook or Twitter. Also, the high number of immigrants and foreign born who, unlike our forefathers, are ready, willing and able to go back home to visit family and friends.
Bottom line is the U.S. is catching up to our Canadian and Australian counterparts when it comes to international travel and I don’t see how that can be anything but a good thing.
Maybe, finally... the media will start treating Americans like the world savvy citizens we are long last becoming.