“originally put in place by a Republican Congress”

Which is supremely ironic, since just like the illusory crisis radicals in Israel and the US had hoped would enable war with the oil-rich regional rival, this only keeps reinforcing that Iran is in compliance, both with this agreement and the NNPT, and refuting the WMD lies those radicals had been peddling.

“but short-term containment is better than”

This was never really about containment. 

It was about moving the goalposts, leveraging economic warfare into additional concessions Iran had no obligation to make, as several violate its rights as a signatory to the Nuclear Non-Proliferation Treaty, and keeping this illusory crisis alive.

“the expansion of Iranian influence”

Is mainly the result of the criminal US-led war in Iraq, and the installation of a Shia government in order to exacerbate sectarian divides that did not exist prior to the war; a bit of the old Colonial trick called ‘Divide & Rule’.