Key Point: This is not what President Trump ran on.
The JCPOA is dead--at least as the Trump Administration is concerned.
For critics of the JCPOA, this represents a move in the right direction; the goal of U.S. policy should be the end of the Islamic Republic and the overthrow of the existing regime in Tehran. As long as this regime exists, no matter how constrained it is by bilateral and multilateral agreements, it will seek to undermine the stability of the established order in the Middle East through overt and covert military means. This position is held in the United States by figures such as Mark Dubowitz of the Foundation for Defense of Democracies and by policymakers such as Sen. Tom Cotton. The desire for regime change is also shared by some in the Middle East, including significant elements of the Israeli and Saudi national security states.
To be fair, few of these voices have called for a military campaign to overthrow the Islamic Republic, and generally for good reason; there is little prospect for success and little appetite for paying the costs necessary to succeed. Still, it’s worth evaluating what a war for regime change might look like. The decision of the Bush administration to commit itself to regime change in Iraq undoubtedly helped lead to the war, even if war was not initially the intention. If the Trump administration similarly commits itself to regime change, then war may come sooner or later.