Nasa doesn't need other partners to go to the Moon, Mars, or anywhere else. To say that we can build a 100,000 ton nuclear powered aircraft carrier by ourselves, but are unable to build a 200 ton manned Mars ship without the aid of other nations is just stupid. The technology for seep space manned missions has been around for decades. There's nothing cutting edge about it. Missions with international partners should be done because we want to do them, not because we have to. The only international space project I can see is a must, would be a modernized and enlarged deep space communications network.