Three rounds of nuclear talks between the U.S. and Iran failed to persuade President Donald Trump that a solution to the two country’s nuclear impasse lay in diplomacy, rather than military action. A perceived lack of progress in the last of those indirect negotiations on Feb 26, 2026, was enough to prompt Trump to green-light a massive onslaught of missiles that has degraded Iran’s offensive capabilities and killed Ayatollah Ali Khamenei and several members of Iran’s senior military leadership.

In response, Tehran has launched strikes across the Middle East, targeting Israel as well as Gulf states that host U.S. airbases. At least three Americans have been killed.

While the scale of the U.S., Israeli and Iranian strikes has taken some observers by surprise, the failure of the talks that led to them was all too predictable.

For diplomacy to be successful, both sides need to agree on the issues subject to negotiation and also believe that peaceful resolution is more valuable than military engagement. This clearly was not the case in the U.S.-Iran nuclear talks of 2025 and 2026.

As someone who has researched nonproliferation and U.S. national security for two decades and was involved in State Department nuclear diplomacy, I know that even under more favorable conditions, negotiations often fail. And the chances for success in the Iran-U.S. talks were always slim. In fact, publicly stated red lines by both sides were incompatible with each other – meaning negotiations were always likely to fail.

Iran wanted the talks confined only to guarantees about the civilian purpose of its nuclear program, not its missile program, support of regional proxy groups or human rights abuses. Essentially it wanted a return to 2015’s Joint Comprehensive Plan of Action, which halted Iran’s development of nuclear technology and stockpiling of nuclear material in exchange for lifting multiple international economic sanctions placed on Iran.

Meanwhile, Trump insisted on limits to Iran’s ballistic missiles and the cutting of Tehran’s support for regional militias. These were not included in the 2015 agreement, with parties ultimately deciding that a nuclear deal was better than the alternative of no deal at all.

False hope

Nevertheless, there had been a slim chance for a breakthrough of late.

While the positions of both the U.S. and Iranian governments had ossified since May 8, 2018 – the date when the first Trump administration withdrew the United States from the Obama-era Iran nuclear deal – there had been some recent movement by Iran, according to former U.S. diplomats involved in negotiations during the Obama and Biden administrations.

With U.S. military building up in the region, Iran appeared more willing to negotiate within the nuclear arena than before. There were plausible solutions to the issue of Iran’s enrichment of uranium capabilities, including maintaining a minimum domestic capacity to develop medical isotopes and a removal of Iran’s stockpile of enriched uranium necessary to build a nuclear bomb.

There was less openness on other points of contention. Notably, there was no movement on ballistic missiles, which had always been a red line. On the eve of the round of discussions held in Geneva on Feb. 17, Trump stated: “I think they want to make a deal.” Iran’s foreign minister, Abbas Araghchi, noted progress over the “guiding principles” of the talks.

But a lot of this optimism appeared to have dissipated by the time the two sides held another round of talks on Feb. 26. While mediator Oman’s negotiators continued to talk of progress, the U.S. side was noticeably silent. Reporting since has suggested that Trump was displeased with the way the talks had gone, setting the stage for the Feb. 28 attack.

Military brinkmanship

The threat of military action was, of course, a continued backdrop to the talks.

The USS Abraham Lincoln carrier group was deployed near Iranian waters in January as a signal of support to the Iranian protesters. The USS Gerald R Ford carrier group joined the buildup before the last round of talks.

Trump warned Iran that “if they don’t make a deal, the consequences are very steep.”

The thinking may have been that Iran, weakened by both the June 2025 U.S.-Israeli strikes and diminished capabilities of Tehran proxies Hamas and Hezbollah, was playing a weak hand in the talks.

Yet Iran also signaled a willingness to engage in military action. In the run-up to the last round of talks, Iran held military exercises and closed the Strait of Hormuz for a live-fire drill. Leaders in Tehran also declared that they would not restrain its response to another attack. The world is seeing that now, with a response that has seen Iran launch missiles across the Middle East and at rival Gulf nations.

Optimism has fallen before

Trump isn’t the first president to fail to secure a nuclear deal, although he is the first to respond to that failure with military action.

The Biden administration publicly pledged to strengthen and renew the Obama-era nuclear deal in 2021. However, Iran had significantly increased its nuclear technical capability during the years that had passed since the Joint Comprehensive Plan of Action collapsed. That increased the difficulty – just to return to the previous deal would have required Iran to give up the new technical capability it had achieved for no new benefits.

That window closed in 2022 after Iran removed all of the International Atomic Energy Agency’s surveillance and monitoring under the deal and started enriching uranium to near-weapons levels and stockpiling sufficient amounts for several nuclear weapons. The IAEA, the United Nations’ nuclear watchdog, maintains only normal safeguards that Iran had agreed to before the plan of action.

Optimism also existed for a short time in spring 2025 during five rounds of indirect talks that preceded the United States bombing Iran’s nuclear infrastructure in June as part of a broader Israeli attack.

A more unstable Middle East

When I worked in multilateral nuclear diplomacy for the U.S. State Department, we saw talks fail in 2009 regarding North Korea’s nuclear weapons program, after six years of on-and-off progress. The consequence of that failure is a more unstable East Asia and renewed interest by South Korea in developing nuclear weapons.

Unfortunately, the same dynamic appears to be playing out in the Middle East.

Military strikes have already killed more than 200 in Iran and across the region. A wider war in the Middle East is a possibility, and should the Iranian regime survive, it may commit to developing nuclear weapons given that the lack of them proved no deterrent to U.S. and Israeli military action.

Talks do not necessarily need an end point – in the shape of a deal – for them to have purpose. Under situations of increased military brinkmanship, talks could have helped the U.S. and Iran step back from the edge, build trust and perhaps develop better political relations – even if an actual deal remained out of reach.

Instead, Trump opted to go a different route.

This article includes sections originally published by The Conversation U.S. on Feb. 17, 2026.

Nina Srinivasan Rathbun does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.