If Donald Trump decides this week to withdraw his endorsement of the 2015 Iran nuclear deal, its fate and the potential for a major conflict will be determined by a complex battle in Congress.
No one is able to predict whether that struggle will lead to a reimposition of US sanctions, the collapse of the agreement and the rapid scaling-up of Iran’s nuclear programme. It could result in a compromise that leaves the deal alive but opens the way for a more combative policy towards Tehran on other fronts.
“We are on a tightrope. We don’t know what will happen,” a western diplomat said.
The congressional contest will pit most Republicans against almost all Democrats, hawks against doves, and will be played out under rules drawn up for a completely different set of circumstances.
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