The US should give Iran a military ultimatum to halt its nuclear weapons program. Thanks to Washington's naivety, Tehran is now on the verge of having enough enriched uranium to produce nuclear weapons, and it's not the JCPOA, with its already tenuous chances of success, but only bold US action that can prevent this. It's time to decisively defend US interests in the Persian Gulf and prove to partners in the region, and Israel in particular, that the US is still a force to be reckoned with.
Allowing negotiations to fail will only lead to exactly what the West aims to prevent: Tehran getting its hands on a full-fledged nuclear weapon and military escalation. The IRGC's terrorist designation is purely symbolic, as the group remains subject to numerous other US sanctions regardless. What stands in the way of restoring the JCPOA is not technical differences but political will, which must be overcome for the sake of peace.
Iran has the legal right to a peaceful nuclear program. Besides, given the economic damage that Washington's unilateral withdrawal from the JCPOA has done to Iran, Tehran should demand significant concessions from the US. Not only must all sanctions be lifted, but Washington must provide binding guarantees against new sanctions and another withdrawal from the deal. Otherwise, its benefits will be short-lived at best, since Trump proved that US can't be trusted to stick to its agreements.