Space has the unfortunate image of being a luxury when it should really be seen as a necessary form of research and exploration, for mining of resources if nothing else. Working with other agencies can make it cheaper in the long run but there are costs that occur because of all of the red national security type tape that must be crossed in order to put some of each countries newest and best technology up in space plugged into other nations stuff.

I agree that there should be more collaboration as space exploration could certainly use the boost but given the undercurrents of mistrust between some of the places involved I don't think that it will happen on a much larger scale for a while.