Wow, what a great example of shut-uppery. Outside of an argument of simplicity for subjugating the US legal system (with respect to patents) to an international body, you indicate a lack of desire for honest debate by simply commenting that anyone who thinks otherwise is an idiot nationalist.
But, I'll ignore that and give you a little food for thought.
First of all, what happens if the international body comes up with standards that are not effective and ultimately damaging? If you've agreed to comply with those standards, how would you go about fixing a system that is broken in your country, but for some reason the international community is unwilling to change? And if you can simply choose to not comply, what value was enforcing those standards in the first place?
Second of all, why is it that the US must change its standards to adapt to Europe/Asia? What the US might feel works and, for the most part, have shown to work with regards to patents is likely not the same as with Europe or Asia. Just because we have a global economy, does it mean that the US has to acquiesce to European/Asian standards all for the goal of simplicity? For as long as the US' market reigns supreme, the US standard is the de facto international standard (with some caveats for other relatively significant markets). Why would the US suddenly take a position from where it leads and comply with standards for which it does not have total control? And for as long as the US is still effectively the leader in invention and entrepreneurship, isn't there something to be said about the US having a better set of laws and a better environment for this? It's far from a perfect system, but I find it hard to believe that others are better and even harder to believe that an international body could even come remotely close.
Thirdly, countries have treaties. The US would be better off negotiating intellectual property treaties with a couple other countries of significance and the rest of the world would have to basically comply. And for as long as the US market reigns supreme, Europeans would not want to prevent its citizens from selling products in the US by not implementing patent standards that are compatible.
Fourthly, if the US believes one of its citizens has proper rights to some IP, why should it necessarily enforce a global patent for a citizen of another country that would hurt its local economy (e.g., instead of producing the product itself, it would be forced to import it instead).
Finally, while a US citizen has the right to have his/her intellectual property protected in the US, why must another country comply? The US should do the best job it can (within reason) to ensure patent protection globally, but other countries are sovereign and if they choose to steal our products, there is little we can do about it. Moreover, those countries uninterested in enforcing US patent rights will be uninterested in complying with an international body anyways.
I realize you might not be a US citizen. My arguments above are simply why the US should seriously consider against a global set of IP standards.