If we did nothing and let Iran bring their nuclear ambitions to fruition, how would that lead to stability for the region and for us? How would WWII have ended up had Germany obtained a nuke before we did? Is there any way, outside of the end of the IRGC and the radical Islamic theocracy, that Iran would partner with anyone else but our enemies?
Why would the GCC countries want Iran to get nuclear weapons and for their current regime to stand? They would become pawns to Iran, China, and Russia.
Also, remember, it was our more 'thoughtful, rational, gentlemanly, and reasoned' Republicans, like HW Bush, who started the ball rolling for advancement of China's economic gains and power in the world.
I’m not lobbying for “do nothing”, I’m warning of the risks of failing.