In 2005 an Iranian delegation visited Belgium. They refused to shake hands with MP Lizin because she was a woman and they threatened to walk away if alcoholic beverages were served although they could choose non-alcoholic ones.
If we would turn that in a Belgium delegation visiting Iran, it would be the same. No handshaking for women and no alcoholic beverages. They don't compromise and you have to abide by what they say.
The same with their nuclear ambitions, with or without a military component. They don't compromise. If they had complied with the IAEA from in the beginning they already would have nuclear power reactors for electricity. But they didn't.
The problem with a nuclear Iran is not having them A-bombs but because of it Saudi Arabia and Turkey also will want them, and maybe others too. What if Iran sells A-bombs or military nuclear technology to Venezuela and or Cuba? It's the chain reaction that will follow if Iran goes (military) nuclear.
Look at what that Pakistani guy (Khan) did. Without interference we would now have had a nuclear Lybia, Iraq and Syria. Can you imagine what could have happend during the revolution in Lybia if they would have had nuclear bombs?
What will happen when a nuclear armed country gets sanctioned by a UN counsil resolution based on chapter seven? Who would give troops to enforce them? Who would risk a nuclear war? Especially if that country has nuclear ICBM's.
BTW, Iran is doing research on nuclear payloads for ICBM's.