The primary leverage the US had to bring about the achievement of JCPOA was the implied threat of military intervention.
That leverage is no longer as powerful. As a result, Iran is going into the negotiations for any future agreement from a stronger position and with even more hardline leadership.
Leah McElrath
“This time, the Iranians will come to the table armed with valuable knowledge: They can survive the worst the Americans can throw at them.”
Bargaining power includes both material capabilities and perceptions, and right now Iran (and everyone) sees the US as weak.
www.wsj.com/world/middle...
www.wsj.com
Tehran has learned it can survive the worst Washington can throw at it, but it still needs sanctions relief to stave off economic calamity.