Unfortunately, some jurisdictions have passed laws that REQUIRE every household to have at least one firearm. I don''t know if these laws will be upheld Constitutionally, but for the time-being they''re on the books.
With regard to what other countries allow or don''t allow, "when in Rome do as the Romans." As an international traveler your US Passport states that you must abide by the laws of the country you''re in, regardless of your opinion of them. If you don''t want to relinquish your right to keep a firearm onboard, don''t visit countries that require you to hand them over upon arrival. It''s really that simple.
Don''t expect folks from other countries to see it your way, especially when the crime rate in their respective country is a tiny fraction of the US crime rate. Clearly, most of them think gun-control in more beneficial to their overall society, than allowing citizens to keep them at home or onboard.
Now, do not take what I''ve written here to mean you should give up your firearms. You do what you think is best for you, and I''ll do what I think is best for me.