If they don't take the initial steps of turning over centrifuges and fissile material, there is a case for using force. Till then, put away the warmongering.
If funding proxy wars is a criterion, Saudi Arabia is much, much worse than Iran. Almost all Islamic terror is of Sunni origin, particularly based on the Wahabi-Salafi doctrine that is Saudi Arabia's biggest export after oil. Iran is Shia, and actually has taken some steps to combat ISIS. This is the reason Saudi Arabia is joining Israel in opposing this deal.
The American people have 2 options in terms of who to trust on this deal:
1. An international coalition comprising the US, the UK, France, Germany, Russia, China and most of the developed world backing them
2. A coalition of 3 parties:
- The Republican party which has a vested interest in not allowing a Democratic president to attain foreign policy success, not to mention the funding that the GOP gets from the US defense companies and oil firms.
- Netanyahua and Likud, who have been crying wolf about Iranian nukes for over 2 decades now
- the House of Said, which seeks to defeat Shia Islam
You all might hate Obama, but there is no way 2 is more credible than 1.