What Factors Drive U.S.-Israeli Differences on Iran’s Nuclear Challenge

Critical Questions by Doreen Horschig and Bailey Schiff

Published April 4, 2025

Since President Donald Trump's second inauguration, strategic differences between the United States and Israel have grown over how best to deal with Iranian nuclear proliferation. The president expressed his aversion to military action early in his inaugural speech, stating that he wants to measure success by "the wars we never get into." This antipathy toward foreign entanglement explains Trump's preference for a diplomatic solution to prevent Tehran from obtaining nuclear weapons, reflected in his recent letter offering negotiations to Iranian Supreme Leader Ali Khamenei. Yet, the president's preference for diplomacy diverges from Israel's favored approach of preemptive military action. Israeli Prime Minister Benjamin Netanyahu applauded Trump's return to a maximum-pressure campaign and also reportedly instructed the military to prepare to strike Iran by mid-2025. Israel's past actions have shown that it is supportive of preemptive airstrikes (Iraq 1981, Syria 2007, and Iran 2024) and covert sabotage campaigns against Iran (July 2020, April 2021, and May 2022). Such fundamental differences between the United States and Israel raise critical questions for U.S. policymakers: Will these diverging signals from the Trump administration undermine strategic alignment, trust, and even coordination between the United States and Israel regarding Iran? And how could shifting geopolitical dynamics around Iran's nuclear program influence this tension?

Q1: What is the Trump administration's strategy for preventing Iran from obtaining nuclear weapons?

A1: The Trump administration's Iran strategy has evolved from a first-term approach focused on maximum economic pressure to a second-term strategy that combines diplomacy, military threats, and sanctions. During his first term, President Trump's approach to Iran was driven by criticism of the Joint Comprehensive Plan of Action (JCPOA), an agreement restricting Iran's uranium enrichment and centrifuge development in exchange for sanction relief. Particularly, he condemned the JCPOA's sunset provisions, alleged failure to constrain Iran's proxies, and inability to limit its ballistic missile program. These concerns led to U.S. withdrawal in May 2018 and the launch of a maximum pressure campaign using sanctions, foreign terrorist designations, and diplomatic isolation to constrain Iran's nuclear ambitions.

In President Trump's second term, the administration appears to be taking an approach that combines diplomatic outreach, military posturing, and sustained economic pressure. Currently, the president is promoting a phased plan giving Iran two months to negotiate a new nuclear deal, backed by the threat of economic and military consequences if Tehran refuses to denounce its nuclear weapons developments. President Trump has also reportedly told aides he wants any future agreement to include restrictions on Iran's support for regional terror groups.

However, Trump's Iran policy has been marked by ambiguity, likely stemming from divisions within his Cabinet, the Republican base, and his conflicting desires to project military strength while crafting a legacy as a peacemaker. Advisors are split on both how to approach Iran (whether through strikes on nuclear sites, resuming sanctions, or dealmaking) and the scope of a potential agreement. For example, Secretary of State Marco Rubio and National Security Advisor Waltz have supported diplomacy backed by the threat of force emphasizing "all actions are always on the table," while Vice President JD Vance has opposed U.S. military intervention to prevent Iran from crossing the threshold. Similarly, Waltz has called for the "full dismantlement" of Iran's nuclear program, while Special Middle East Envoy Steve Witkoff instead emphasized "a verification program" to mitigate fears over weaponization.

Although the current maximum-pressure campaign can appease more isolationist neoconservatives, reassure traditional Republicans that military action remains an option, and address Israeli concerns about the impact of sanction relief on Iran's proxies, this balancing act, whether by design or the product of a split cabinet, is unlikely to hold. Once the two-month deadline expires, the administration will be forced to choose between escalation, negotiation, or retreat.

Q2: How does Israel view the threat of Iran's nuclear program, and what are its preferred policy options?

A2: Israel perceives Iran's nuclear program as an existential threat, resulting in a multifaceted strategy to prevent Tehran from acquiring nuclear weapons. This approach includes military action and covert operations. The "Begin Doctrine," established after the 1981 strike on Iraq's Osirak reactor, underscores Israel's commitment to preemptively neutralize potential nuclear threats in the Middle East.

In recent months, as Iran advances its nuclear capabilities, Israel has intensified its preventive measures. For example, on October 26, 2024, Israel conducted an airstrike that significantly damaged Iranian defenses, demonstrating its readiness to use force when deemed necessary. The October 7, 2023, Hamas-led attack has shifted Netanyahu's willingness to take risks. While he had decades to strike Iran, he remained cautious and did not follow through. Now, politics in Israel have changed, and Netanyahu's political position may increase his incentives for preventive action.

Historically, Israel has remained skeptical of diplomatic solutions like the JCPOA. Israel believed that the treaty's sunset clause would allow key restrictions to expire over time, that the International Atomic Energy Agency would not have unrestricted access to inspect the facilities, and that allowing uranium enrichment would set a dangerous precedent that would encourage regional proliferation.

Netanyahu was especially vocal in his concern over the nuclear deal and diplomatic approaches. He denounced the JCPOA as a "historical mistake," resulting in a bitter disagreement with the Obama administration and strained U.S.-Israeli relations at the time. Netanyahu's views on diplomacy with Iran have since changed little, and he not only welcomed the first Trump administration's withdrawal from the JCPOA in 2018 as a "historical move" but also supported a return to a maximum pressure campaign in the second Trump administration.

Netanyahu further emphasized his aversion to the deal: "Arrangements that do not dismantle Iran's nuclear infrastructure do not stop its nuclear program and only provide it with funds that will go to terrorist elements sponsored by Iran." Israel wants the United States involved in more forceful measures, including military options. A strike against Iran's hardened, dispersed nuclear sites would require sustained attacks, something Israel can execute in some capacity but would require U.S. involvement to be effective, especially given the need to counter any Iranian retaliation.

Q3: To what extent do U.S. arms sales to Israel and regional deployments reflect or contradict Washington's stance on Iran?

A3: U.S. arms sales to Israel and regional deployments do not always seem fully aligned with President Trump's preference for diplomacy. One of his first executive orders authorized shipments of MK-84, 20,000-pound bunker-buster bombs to Israel, which had previously been withheld due to concerns of potential use in Rafah in the Gaza Strip. While these bombs lack the penetrative capability to strike deeply buried or fortified sites, like the Fordow or Natanz, they could be used in a joint-air campaign to target above-ground or lightly reinforced facilities tied to Iran's nuclear program (e.g., centrifuge, ballistic missile component production, or research sites). Subsequently, the United States stationed B-2 bombers on Diego Garcia Island in the Indian Ocean, raising questions about the U.S. contingencies with Iran, as if equipped with GBU-57 Massive Ordnance Penetrators, could be capable of destroying heavily fortified nuclear sites in multiple successive strikes. Compounding these signals, the United States launched air and naval campaigns on targets in Yemen controlled by the Houthis, an Iranian-backed militia, aiming not only to open international shipping lanes but to send a warning signal to Iran.

Taken together, these arms transfers, bomber deployments, and recent strikes in part represent strategic posturing intended to pressure Iran into nuclear negotiations before the two-month deadline. By simultaneously bolstering the credibility of its willingness to use force while signaling a mild tolerance for an Israeli surgical strike on Iran's nuclear program, the administration appears to be leveraging the threat of escalation as a bargaining chip. Given Trump's negotiating style often emphasizes strategic ambiguity, unpredictability, and oversized demands, he likely views a more assertive military posture as a source of leverage rather than a contradiction. This perspective is underscored by his recent threats that "if they don't make a deal, there will be bombing . . . the likes of which they have never seen before."

Q4: How have the strategic differences with Iran affected the Trump-Netanyahu relations?

A4: On its surface, President Trump and Prime Minister Netanyahu project a close relationship. For example, Trump previously welcomed Netanyahu and his wife Sara at Mar-a-Lago, moved the U.S. embassy from Tel Aviv to Jerusalem upon Netanyahu's urging, mused with Netanyahu about a U.S. takeover of Gaza, and invited the Israeli head of state as the first foreign leader to visit the White House in his second term. During this first meeting, Netanyahu aligned Israel's security objectives with U.S. policy, portraying Iran as a direct and immediate threat not just to Israel but to U.S. interests.

We also see eye to eye on Iran. That's the same Iran that tried to kill us both. They tried to kill you, Mr. President. They tried, through their proxies, to kill me. But we're both committed to rolling back Iran's aggression in the region and ensuring that Iran never develops a nuclear weapon.

By framing Iran as the orchestrator of regional terrorism and directly linking its proxies to attacks on both nations, Netanyahu tries to justify aggressive preemptive measures, including military strikes and covert operations. However, Trump, in his second term, has not taken Netanyahu's advice on how to approach Iran as he has in the past. In 2018, both shared their objection to the JCPOA. Trump had received Israeli intelligence obtained by the Mossad through their raid of secret Iranian nuclear files. The president trusted Netanyahu's judgment that withdrawing from the deal was the better option while also seeking to undo it as a signature Obama foreign policy achievement.

In the last few years, since the U.S. withdrawal from the deal, Iran has ramped up its nuclear developments, lifting the cap on its stockpile of uranium, expanding its enrichment capabilities, and resuming activities at its nuclear facilities. Iran's actions may have prompted Trump to reconsider diplomacy in his second term, signaling a shift from the previously aligned U.S.-Israeli stance that negotiations were largely ineffective. While Netanyahu has not directly commented on Trump's offer to engage Iran in diplomatic talks, his team has been actively pushing for the United States to impose a time limit on the maximum pressure campaign before considering alternative measures, including military action. In late March, a delegation led by Israeli Strategic Affairs Minister Ron Dermer visited Washington to discuss these policy concerns and Israel's preferred course of action.

As Trump navigates diplomatic overtures and strategic posturing, Israel's skepticism of negotiations could create friction, particularly if the administration pursues an agreement that does not meet Israeli security demands. With the two-month window for diplomacy closing, the extent to which the allies can reconcile their differences will be critical in determining whether the U.S. approach ultimately leans toward engagement or escalation.

Q5: Beyond the United States and Israel, what role do other actors play in the geopolitical dynamics of Iran's nuclear program?

A5: Russia, China, the Gulf states, and the E3 (Germany, the United Kingdom, and France) are expected to shape future negotiations, either as counterweights to Western influence or as mediators promoting regional stability. Russia and China recently held trilateral talks with Iran, emphasizing that renewed dialogue must be based on "mutual respect" and accompanied by the lifting of all sanctions. While both countries have historically opposed Iranian nuclear weapon development, today, subtle differences underlie their approaches: China has a vested interest in ensuring the free flow of Middle East energy exports, while Russia, more self-reliant on oil, views a potential nuclear deal as a mechanism to extract U.S. concessions. These distinctions suggest Russia has a higher tolerance for regional instability, whether stemming from a limited conflict, collapsed negotiations, or Iran nearing the nuclear threshold. Still, Moscow is expected to play a role in future negotiations, as President Trump reportedly asked President Putin to mediate a nuclear agreement between the United States and Iran, a request Putin later agreed to.

Europe and the Gulf states will be critical to sustaining a future deal and ensuring regional buy-in. While President Trump requested direct talks, E3 representatives met with Iranian officials four times between November 2024 and March 2025 to discuss the scale and scope of potential negotiations. The E3, instrumental in crafting and preserving the JCPOA after U.S. withdrawal, will want to participate in future negotiations, especially given that the JCPOA snapback mechanism is set to expire in October. Engaging with the United Arab Emirates (UAE) and Saudi Arabia will also be vital to mitigating regional threat perceptions and legitimizing the agreement among the Gulf states. Notably, Trump's March letter was delivered by Anwar Gargash, a senior diplomatic adviser to the UAE, who requested to host the talks. However, Iran signaled that it would prefer Omani mediators when returning a response.

Russia and China's support for negotiations and European and Gulf states' involvement introduce competing interests that may undermine or reshape U.S.-Israeli coordination. The U.S.-Israeli relationship on Iran's nuclear challenge is shaped by a mix of strategic alignment and diverging preferences. While both countries view Iran's nuclear ambitions as a significant threat, their approaches diverge: the second Trump administration balances diplomatic engagement with military deterrence, whereas Israel favors preemptive action and sustained pressure. The two-month negotiation window set against intensifying geopolitical dynamics and regional military posturing will only deepen this underlying challenge of maintaining alignment.

Doreen Horschig is a fellow with the Project on Nuclear Issues at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Bailey Schiff is a program coordinator and research assistant with the Project on Nuclear Issues at CSIS.

Programs & Projects