Is the International Space Station the only Space Station shared by every country?

Answer 1

Currently right now the International Space Station is the only space station in orbit. It has however been the only space station with such international participation that it can be really be considered international. Countries, including the US, have sent astronauts to Russia's former space station Mir. Just because the International Space Station is international, doesn't necessarily mean that every country uses it. Their are 15 countries that contribute to the ISS program including the US, Russia, Canada, Japan, and several European countries.