Both sides faced internal political pressures. In Iran, hardline factions opposed any agreement seen as capitulation. In the United States, political polarization made any deal vulnerable to reversal depending on electoral outcomes.
These constraints made sustained diplomacy extremely difficult.
The Collapse of Momentum
By 2020, the situation had escalated significantly. The killing of Iranian General Qassem Soleimani in a U.S. drone strike marked one of the most dangerous moments in U.S.-Iran relations in decades. Iran responded with missile strikes on bases housing U.S. forces in Iraq, and the region briefly feared wider war.
At this stage, diplomatic momentum had largely collapsed.
The idea that Iran had “missed chances” assumes that stable, good-faith negotiation conditions existed long enough for a breakthrough. Critics argue instead that each escalation—sanctions, military actions, and counteractions—closed the window further.
Strategic Miscalculations on Both Sides
A more nuanced interpretation suggests that both Washington and Tehran made strategic miscalculations.
For the Trump administration, withdrawing from the JCPOA without securing a replacement agreement immediately may have reduced leverage over time, rather than increasing it. While sanctions hurt Iran economically, they did not produce a new deal under the desired terms.
For Iran, escalating nuclear activity and regional tensions increased international suspicion and reduced diplomatic flexibility, even among European allies who had initially tried to preserve the original agreement.
In this sense, neither side fully achieved its objectives.
The Role of International Mediators
Throughout this period, European powers attempted to salvage diplomacy. Mechanisms such as INSTEX (a financial channel designed to bypass U.S. sanctions for humanitarian trade) were introduced, but had limited impact.
