Like one country ( Iran) violating the NPT, while all the rest of the signatories have to abide by it?
This is why we need an equitable system of international justice. Because the US and Israel are both in violation of international treaty obligations as well as international law, and they are being allowed to get away with it. All countries would need to have the same standards applied to them. If the US was not posing a credible threat to Iran, Iran would not need to beef up its defensive capabilities. The treaty violations of the US precede those of Iran, so that is the issue that should be addressed first.