Convene the E3 to Address the Iranian Nuclear Threat

• In its first 100 days, the Trump administration should convene the United Kingdom (UK), France, and Germany—the E3—to coordinate a strategy for dealing with Iran’s nuclear program, including a possible negotiated settlement.
• Iran is closer than ever to having the capability to produce a nuclear weapon; the Trump administration should ensure that the regime does not make the decision to pursue it.
• The Trump administration should have a coordinated sanctions and negotiation strategy with the E3 to formulate a collective negotiation strategy before the Joint Comprehensive Plan of Action’s snapback mechanism expires in October 2025.

When Donald Trump is sworn in as the 47th U.S. president, Iran will be closer than ever to having the capability to produce a nuclear weapon. The only thing standing between Iran and the bomb is a decision by Supreme Leader Ali Khamenei on whether to move ahead. With the second-strike threat of Hezbollah now severely diminished following Israel’s military operation in Lebanon, and the Iranian regime’s air defenses rendered inoperable following Israel’s direct military strike on Iran in October, many in the regime likely see a nuclear weapon as critical to deterring threats to the sovereignty and stability of the revolutionary government.¹ Beginning on “Day 1,” the Trump administration must make every effort to impress upon the regime that the opposite is true.

In his first term, President Trump took unilateral action to pressure Iran. In leaving the Iran nuclear deal, he put Washington at odds with its European partners who chose to remain party to the agreement. In his second term, Trump will find the positions of the United Kingdom, France, and Germany have shifted toward favoring a more muscular approach to dealing with Iran’s nuclear program since his previous term. As such, the administration should focus its energies in the first 100 days on reaching a coordinated policy position with the UK, France, and Germany to deal with Iran’s nuclear program.

While the Iranian regime has taken significant steps toward acquiring the bomb, the supreme leader also has signaled his willingness to pursue another negotiated settlement to achieve sanctions relief.² Simultaneously, Iran has continued stockpiling highly enriched uranium and has blocked International Atomic Energy Agency (IAEA) inspectors from accessing key nuclear sites, which drew a censure from the IAEA’s Board of Governors in November 2024.³ Just as Tehran has sent mixed signals by advancing its nuclear program while messaging its willingness to talk, the second Trump administration has similarly sent mixed signals to Iran. Trump’s policy advisors have indicated that he would move swiftly to resume “maximum pressure,” an array of sanctions and focused enforcement meant to choke Iran’s oil exports.⁴ However, President Trump has indicated his preference for a negotiated settlement with Iran.⁵ In November 2024, Elon Musk, a Trump advisor, reportedly met with Iran’s United Nation (UN) ambassador to discuss how Washington and Tehran might reduce tensions.⁶

These policies of pressure and negotiation, of course, are not mutually exclusive. If these policies are properly sequenced, Trump administration officials likely assess they can pick up where they left off and pressure Tehran into negotiating a better deal.

To improve its chances of entering negotiations from a position of strength, the Trump administration should immediately engage the United States’ European allies. During his first term, Trump unilaterally withdrew from the Joint Comprehensive Plan of Action (JCPOA), the multilateral nuclear deal the United States had struck with Iran in 2015 alongside the United Kingdom, France, Germany, Russia, China, and the European Union. However, these European nations and China—known as the P5+1—remained party to the agreement. When Washington reimposed sanctions, it did so alone.⁷

When President Trump restores maximum pressure on Iran, he is likely to find the UK, France, and Germany—known as the E3—far more receptive to coordinating a pressure campaign with Washington. For more than a year, the E3 quietly has sought to push the United States to focus its attention on Iran’s nuclear program and agree to more confrontational diplomatic responses to Iran’s nuclear advances. The Europeans wanted to censure Iran in June 2024, following an IAEA report that Iran had amassed its largest stockpile of highly enriched uranium to date.⁸ Reportedly, the Biden administration argued against censure, fearing it would push the Iranians to behave more rashly.⁹ While the Biden administration voted with the E3 in favor of censure in November 2024, the Europeans have been pressing Washington for a more aggressive approach to Iran for many months.

Within the first 100 days, the Trump administration should convene the E3 to coordinate a strategy for dealing with Iran’s nuclear program. The United States and the E3 have several key decisions to make before the JCPOA’s snapback mechanism expires in October 2025. By declaring Iran out of compliance with the JCPOA, the United States and E3 could trigger the immediate reimplementation of UN sanctions on Iran, thus creating a critical opportunity for the United States and the E3 to leverage snapback in pursuit of a deal. Whether the United States and the E3 decide to implement snapback immediately or use the threat of snapback as negotiating leverage, the administration will be more successful if it works in cooperation with the UK, France, and Germany and approaches Iran with a collective position. While the supreme leader is eager for sanctions relief, Tehran also may seek to use negotiations to run out the clock on snapback, robbing the West of a powerful sanctions tool. While Russia and China—two nations that have grown significantly closer to the Iranian regime—likely would undercut the economic impact of snapback sanctions by continuing to trade with and support Iran, Tehran still fears the international stigma of being under UN sanctions once again.

Trump’s return to office coincides with Iran standing closer to a nuclear weapon than ever before. In the past year, Tehran has demonstrated a greater tolerance for risk than it has in the past—twice attacking Israel directly and once attacking Pakistan, both nations that reportedly have nuclear capabilities of their own. The White House must act fast or risk Iran miscalculating that regional aggression and nuclear breakout are the best options to preserve the regime. While time is of the essence, and a deal to prevent Iran from obtaining a nuclear device is more important than ever, President Trump should avoid racing to the table with Tehran. First, he should do everything he can to maximize his leverage by making his first call to the E3 to coordinate a common negotiating position. Now is the time to come to agreement with the United States’ European partners on how to leverage snapback sanctions before they expire and formulate a collective negotiation strategy. With little time on the clock and Iran so close to a weapon, doing so will deliver the Trump administration the best opportunity to prevent Iran from becoming the world’s 10th nuclear power.