As long as America is paying for the vast majority of space exploration, the achievements belong to us. We spend almost 3 times the entire rest of the world combined, about $60 billion to $22 billion a year. Global achievement requires global contribution. Leveled for GDP, the rest of the world would need to spend about $160 billion a year more than they are.

Editing in more details from posts I've made before:

The total 2010 US Space budget was $64.6B. The entire rest of the world combined spent only $22.5B. NASA's 2010 budget was $18.7B, 83% of the spending for the rest of the world. The entire ESA budget is a paltry $4.6B, while the EU has a higher GDP than the US.

Not all US space spending is through NASA. For example, the GPS system is not included in NASA's budget, it's spearheaded by the Air Force Space Command, and comes out of the Defense budget. And before anyone says that Defense space spending should not be included, keep in mind that will dramatically reduce the overall global space budget which does include defense spending. For example, the European Galileo satellite navigation system, which has cost some €20B, is included in the ESA budget, so it would have to be taken out in order to compare with NASA, our civilian space program.

If the rest of the world spent as much as the United States on space exploration by GDP, global space spending would be 4.1 times higher than it is today. $267B instead of $87.1B.