re: 10 + reasons
International cooperation works if the partners work under the same kinds of rules, agreements and technology levels.
The HST involved the ESA for 15% and I've never read about complains about it.
The first Spacelab was built by the ESA, flown by NASA and right after its first flight, given to NASA (which meant ESA lost its rights to it and NASA was satisfied by the technology level).
For the ISS: if it were not for the Russian Soyuzes and Progress vehicles, there would be nobody in space, now.
Luckily, the ISS doesn't only depend on the Shuttle.
Raoul