If past is prologue, even under the scenario in which Iran walks away from the JCPOA, Iran will likely escalate its nuclear program only incrementally not aggressively so as to avoid crippling economic sanctions or military strikes. Despite Iranian President Hassan Rouhani’s statement that if the West does not provide Iran with the nuclear deal it wants, Iran “will go back to the old path, stronger than what they [the West] can imagine,”27 Iran has historically moved cautiously.
For example, between 2008 and 2013, Iran only increased its operating centrifuges by an average of about 1,000 per year at the Natanz facility.28 During this five-year period, during which sanctions on Iran escalated significantly, Iran’s nuclear program expanded incrementally, as demonstrated in the chart above.29
While the increases over the five year period were concerning, Tehran was careful not to engage in massive nuclear escalation that could trigger more crippling economic sanctions or military strikes. Based on this history, it is reasonable to expect Iran to maintain this careful policy even if it walks away from the current deal and refuses to renegotiate based on Congress’ required amendments. Indeed, the risks are the same. A rapid breakout by Iran would likely lead to a military response, as presidents from both parties have repeatedly pledged to use military force if necessary to prevent an Iranian nuclear weapon. Iran knows that it would ultimately lose such a war.