Neither the US nor the rest of the world can prevent Iran to acquire nuclear weapons if Iran really wants to have them. Several countries can develop nuclear weapons if they want, but they have decided to not do that. No one forced them, they did that of their own free will, or it benefited them to not develop nuclear weapons. An Iran with nuclear weapons will neutralize Israel's and might trigger an arms race in the region, which might balance and stabilize the region. The major problem if we have Iran and Israel with nuclear weapons is, they don't communicate directly to each other so misunderstandings can have consequences. During the Cold War, the US and the Soviet Union were communicating. What could happen during the Cuban missile crisis if they were not communicating?
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