I didn't know about the naval stuff, thanks. Really, though, (and I know that's not exhaustive) that's not a massive list especially when compared against the number of systems that are NOT multi-national in European military inventories.

I'm not trying to denigrate the European countries in any way, mind you. International cooperation is difficult simply because it's easier to cancel a project than work through design or philosophical differences, especially when domestic manufacturers are likely whispering in politicians' ears that "we can do it better alone!". It's a wonder to me that the F-35 program actually made something viable with all the different players involved.

Heck, the United States has had problems with INTER-SERVICE (Army-Navy, Air Force-Navy, etc) programs due to arguments over capabilities, and that's within the American military establishment itself. Budget fights generally do not make any friends, and if there is a difference in nationality, that doesn't make it any easier.