The seventh round of talks in Vienna this year between the parties to the 2015 Iran nuclear deal and the United States is struggling to pick up momentum. The accord has been in trouble since then president Donald Trump in May 2018 withdrew the US from the Joint Comprehensive Plan of Action (JCPOA), as the deal is formally known, and reimposed sanctions. Although significant progress on reviving the accord was achieved in the first six rounds earlier this year, held since US President Joe Biden took office, Washington is now considering alternative strategies as negotiations stall.

At its heart, the JCPOA entails a trade-off in which Iran receives sanctions relief in exchange for restrictions on its nuclear program. The Islamic Republic has gradually distanced itself from the deal’s restrictions in response to the reimposition of US sanctions, albeit stopping short of walking away from the JCPOA. The current contention between the two sides mainly pertains to the lifting of Trump-era sanctions and Iranian nuclear advances.

While vaguely defined thus far, the US ‘Plan B’—in case efforts to revive the JCPOA fail—will probably align with ‘offshore balancing’ approaches as Washington works to shift focus to areas of vital interest, such as China. From an Iranian perspective, this scenario will require the US to increase pressure on Iran while avoiding the lure of spiraling engagement in the Persian Gulf region...