Given that the senate can pass a normal law with only 60 votes (should be 50, but that is another story in American dysfunctionality), and given that a normal law has the same legal authority in the US as a treaty does, it seems ridiculous to me that we couldn't simply pass a law that enforces the articles of a treaty without actually calling it a treaty and thereby bypass the necessity of a 2/3rds majority. However, I suppose requiring 2/3rds support for treaty makes us more honest because if a treaty has that much support it is far less likely to get repealed because it needs to have overwhelming and bipartisan support before we commit ourselves to it.. The concession I heard that was to be given to the republicans in order to obtain their support for this treaty was that America would "modernize" its nuclear arsenal, which basically means we would come up with new state-the-art nuclear weapons. Along this line of thought, and some others that were notable, it would be more rational for START treaties put limitations on the destructive power of the countries arsenals instead of or alongside limitations on the actual numbers of weapons that are allowed to be had because otherwise a loophole allowing inequity, though it wouldn't be the only one, is established. One way I have heard this treaty described is that Russia was going to reduce its arsenal anyway because its expensive, more than sufficient, and takes funding from conventional forces, and by having a treaty Russia can get what are therefore in effect free concessions from the US. At any rate, I expect this treaty to be passed in the US, but we will have a better idea of whether or not it will be after the Obama administration briefs the senate; much of the Republicans' complaints have been that they just want information on things like verification.