News that John Bolton has been named President Trump’s new national security adviser – following the appointment of harsh Iran critic Mike Pompeo as Secretary of State – adds to mounting evidence that the United States will quit the Joint Comprehensive Plan of Action in May.

Under now ex-Secretary Rex Tillerson, the Trump administration had been pressing Britain, France and Germany to agree to renegotiate the Iran deal in response to the US president’s ultimatum in January to fix it or he would nix it.

In response, France proposed new sanctions addressing Iranian missile tests and regional involvement. A confidential document cites “transfers of Iranian missiles and missile technology” to Syria and allies of Tehran, such as Houthi rebels in Yemen and Lebanon’s Shi’ite Hezbollah.

In addition to missile testing and regional issues, US negotiators have pressured the Europeans to renegotiate so-called “sunset clauses” that limit aspects of Iran’s nuclear program and to toughen provisions providing access to Iranian military facilities for inspections. Trump wants the limitations on Iran to be permanent and access to military facilities automatic instead of subject to negotiation.

France has not included these other issues in its proposal. Changing the expiration dates for restrictions on the nuclear program or access to military facilities would breach the JCPOA. On the other hand, the regional question was never included in the nuclear negotiations. Missiles were only partly addressed under the UN Security Council resolution, which codified the JCPOA; it only calls on Iran not to test missiles capable of carrying a nuclear warhead.

The European Union has reached no decision on the French proposal. The EU has refused to renegotiate the JCPOA, a standpoint also supported by the other parties to the deal including Russia and China.

Iran, which according to the International Atomic Energy Agency has fully implemented the deal, has also refused any renegotiation. President Hassan Rouhani has said that Iran will stick with the agreement as long as it is beneficial for his country—even if the United States leaves. The tone changed recently, however, when Deputy Foreign Minister Abbas Araghchi said, “We have told the Europeans that if they can’t keep the US in the deal, Iran will also leave it.”

The front lines are hardening and the deadline is fast approaching. The limited proposal on the table was likely not enough for Trump and almost certainly will not impress Pompeo and Bolton.

The EU’s High Representative for foreign policy, Federica Mogherini, has strongly underlined the importance of the JCPOA, which the EU regards as a signature diplomatic achievement. “This is not a bilateral agreement,” Mogherini has said. “This is not an agreement that involves six or seven parties. This is a UN Security Council Resolution with an annex. And as such, all Member States of the United Nations are considered to be bound to the implementation of it. So, it doesn’t belong to one country, to six countries, to seven countries, to the European Union—it belongs to the international community.”

Consequently, no one country should able to destroy it. Nevertheless, the probability that the US will exit the deal and that the JCPOA will collapse is increasing.

Transatlantic tensions over Iran’s nuclear program are nothing new. When the E3 – Britain, France and Germany — in 2003 initiated a dialogue with Iran, in order to avoid a military confrontation like the one in Iraq, the US was vehemently opposed. Bolton, then under secretary of State for Arms Control and International Security, pushed to refer Iran to the Security Council to enable imposing multilateral sanctions on Iran. The E3 initiative derailed this plan. Bolton was extremely critical of the E3 negotiations, saying, “Even if I agreed with seeking a deal with Iran, which I definitely did not, what was gained by pushing to engage now? Why not wait until Iran was referred to the Council, where we could put some pressure on them, rather than agreeing to talk beforehand?”

The Europeans finally agreed to report Iran to the Security Council in 2006, after the election of the hardline Mahmoud Ahmadinejad as Iranian president and the escalation of Iran’s uranium enrichment program, which had been largely suspended from 2003-2005. In referring Iran to the Council, the European goal was to bolster new negotiations. The US goal was pressure and sanctions. Effectively, the US and Europeans only worked together as partners under the Obama administration, when both saw enhanced sanctions as supporting diplomacy. The European sanctions made the difference, given that US trade with Iran was already largely banned. Although the EU coordinated the entire 12-year process, negotiations did not succeed until the US and Iran fully engaged bilaterally from 2013-2015.

With the inauguration of Donald Trump, transatlantic policies have again diverged.

The EU is between a rock and a hard place. According to its 2016 global strategy, the EU is committed to a multilateral, rules-based international system supporting the full implementation and enforcement of multilateral treaties and regimes.  According to the EU security strategy of 2003, the transatlantic link is the backbone of its foreign and security policy. The EU’s framing of the Iran negotiations over 12 years was ultimately successful in sustaining both a multilateral rules-based system and transatlantic ties. But with the JCPOA’s future thrown into question, so, too, is the EU’s continued ability to maintain both these pillars. The EU now faces a choice: multilateralism or transatlantic relations.

The double foundation of the EU’s role as a global actor is not the only victim if the deal unravels. Non-proliferation diplomacy will receive a decisive blow. During the month of May, the US president may not only exit a hard-won multilateral, diplomatic arrangement to prevent Iran from acquiring nuclear weapons but, at the same time, exert pressure to achieve a diplomatic success with North Korea.

The North Koreans will observe extremely closely what happens with the JCPOA. States that have given up nuclear weapons programs, such as Ukraine, Libya and Iraq, have not become examples of prosperity and peace after they agreed to relinquish these technologies. The JCPOA is the only example so far of an agreement that fosters nonproliferation without a military outcome. That, too, is now in jeopardy.

Tarja Cronberg is a Distinquished Associate Fellow at the Stockholm International Peace Institute, SIPRI. She is a former member of the European Parliament, the chair of its Iran delegation and the author of “Nuclear Multilateralism and Iran: Inside the EU Negotiations,” Routledge Focus, 2017.