you cannot carry it in your carryon-you will not be able to get through security at the airport. Just put it in your checked baggage and you should be fine.

Can’t take it in your carry-on on any airplane (US or Europe). No problem on trains or generally on the ground.

Just go to switzerland and buy the real thing.

Ditto to all that was said. Although you can get all the knives online and in the U.S. or anywhere in the country, it is cool to say you got it in Switzerland. If that part of the trip is early, wait to get one there.

Happy Trails,
Rick