The United States and the Islamic Republic of Iran have reached an agreement to end the war. When it launched its first strikes alongside Israel in late February, the US announced that its objectives included regime change, dismantling Iran’s nuclear program, dismantling or at least degrading its missile and drone programs, and terminating or reducing its support for non-state armed groups in the region, especially Hezbollah in Lebanon, Hamas in the Palestinian Territories, and the Houthis in Yemen. After more than 100 days of conflict, Washington has not come close to achieving any of these objectives.

On the surface, this result might appear counterintuitive: there is a massive power imbalance between the US, still the world’s dominant military power, and Iran, a regional power hampered by decades of sanctions and diplomatic isolation. What makes the outcome even more surprising is that what was long thought to be one of the Islamic Republic’s most valuable strategic assets – the Axis of Resistance, a network of Iran-backed armed groups across the region – did not play an important role in the conflict.

Iran’s apparently paradoxical success can be explained by a combination of factors. Geography played a major role in Iran’s success and in hampering the US. To state the obvious, Iran controls the northern shore of the Persian Gulf, including the critical Strait of Hormuz. This gives it a permanent ability to threaten maritime shipping at one of the most crucial chokepoints for the global economy. The mountainous terrain in southern Iran magnifies this advantage, allowing Iran to hide multiple small sites for stockpiling and launching missiles and drones. This capability is a permanent threat that can only be managed, not eliminated, as long as the Islamic Republic is in power. Now that Tehran has set the precedent, what was widely known in theory must now be accepted in practice: Iran can, for the foreseeable future, threaten to close the Strait again, in full or in part, to extract concessions from its adversaries. This will act as a powerful constraint on Washington’s ability to pressure the Islamic Republic.

At the political level, the essential variable was that the war was existential for the Islamic Republic. Unlike past rounds of violence or peaks in tension, as soon as the US and Israel openly signaled their intent to overthrow the Islamic Republic – however inconsistent they were in their articulation of the war’s other objectives – Tehran radically shifted its approach. Because it was fighting for its very survival, the Islamic Republic’s leadership was willing to absorb significant pain, both militarily, from the roughly 20,000 American and Israeli strikes, and economically, from the American blockade. At the same time, for the US and its easily distracted and famously impatient president, this was a war of choice. The willingness to absorb the economic and political cost of moderately higher oil prices was therefore lower. This massive divergence in the two sides’ pain thresholds goes a long way to explaining why Tehran was able to exercise such patience, while the Trump administration openly signaled its weaker hand by rushing into talks. For the Islamic Republic, the combination of its massive repressive capacity – amply demonstrated in January 2026 – with the reality that a sizable minority of the population still supports the regime was enough to sustain its government despite bombs and the blockade.

A third factor was that the regime had long been preparing for a large-scale American attack. This enabled it to rapidly implement its “mosaic” defense strategy, in which decision-making was decentralized, allowing commanders to act autonomously, even when the chain of command was under pressure and communications were at risk of breaking down. The regime also had long-prepared contingency plans to replace leaders and military commanders after their assassination. Succession, even at the very top of the regime, occurred fairly smoothly, allowing for continuity in governance and operation of the armed forces, despite dozens of senior officials being killed.

Finally, it was easier for the Islamic Republic to spoil political developments and hinder its adversaries than it was for the US to pressure it to change its behavior. The US can certainly hurt the Islamic Republic economically and militarily, but Washington vastly overestimated its ability to compel Tehran to overturn decades of foreign policy practice. This dissonance was illustrated by the US’s consistent bragging about the number of missiles, drones, launchers, stockpiles, and production sites that it damaged or destroyed. The numbers may have appeared impressive on the surface; however, in practice, what mattered was Iran’s continued ability to target shipping in the Strait of Hormuz and its Arab neighbors in the Persian Gulf, a capacity it retained even if only a portion of its drones and missiles survived.

While the US failed to achieve its objectives and Iran undoubtedly made geopolitical gains, it would be a mistake to assume that the Islamic Republic is the war’s clear winner. The massive American-Israeli bombing campaign did cause significant damage to Iran’s economic and military infrastructure. More importantly, the Islamic Republic remains vulnerable domestically. Its economy is in shambles, not just from the war, but from decades of sanctions and mismanagement, while the regime is highly unpopular and remains in power in part through its brutal repressive capacity. It is a matter of when, not if, Iranians return to the streets in large numbers to protest their government. While the proposed deal appears to involve significant economic relief for Iran, several steps remain before these benefits could materialize and trickle down to the population.

This new dynamic in the Persian Gulf carries implications for the Axis of Resistance. The role of the Axis in Tehran’s strategy has been diminished. Originally, one of the main purposes of Iran’s support for Hamas and Hezbollah was deterrence: the threat of costly retaliation by its Axis partners was meant to deter the US and Israel from directly attacking Iran. This strategy has failed on multiple occasions since 2023 as most Axis members have become weaker as a result of heavy military pressure from Israel, especially Hamas and, to a lesser but still significant extent, Hezbollah.

The Axis is now, in some respects, a liability for Iran. For all its support to Hezbollah over the decades, not only has the group failed to boost Iran’s defenses, it has needed Iran to come to its defense instead. Iran had to work hard to include Lebanon in the June ceasefire agreement, in part to protect it against continued Israeli strikes. This will raise further difficulties: in the high likelihood that Israel strikes Hezbollah again, Tehran will have to decide whether to risk the agreement with the US, or appear weak by looking the other way.

The Houthis are the exception in the weakening Axis of Resistance. Unlike their non-state counterparts, they are stronger today compared to 2023. Domestically, their position remains unchallenged, thanks to a combination of Iranian support and the relative weakness of their adversaries. Moreover, they have emerged in recent years as an ambitious and assertive regional power. They did little to intervene in the US-Iran war, in part because US and Israeli strikes in 2025 were sufficiently costly to enough to tilt their cost-benefit calculus towards greater caution. Nevertheless, they retain the capability to shut down, or at least seriously hamper, traffic in the Bab al-Mandab, another crucial maritime chokepoint at the southern tip of the Red Sea. This is an option they are keeping in reserve, to be used in the event of another existential threat to the Islamic Republic or to their own domestic supremacy, or perhaps to counter heavy Israeli pressure on Hezbollah. In parallel with the Iranian threat to the Strait of Hormuz, this means that the Axis can hold the global economy hostage for the foreseeable future.

In sum, the war demonstrated that the Axis of Resistance now plays a lesser role in Iran’s strategy of deterrence and power projection than had long been assumed. Israel has not decisively defeated Hamas and Hezbollah, but it has significantly weakened them. Their ability to impose costs on Israel or the US has therefore lessened, reducing their strategic value to Tehran. This implies that in Tehran’s eyes, the Houthis’ importance has increased. Once a loosely organized militia in a remote corner of Yemen, they are now the dominant power in the country and a regional power able to check Saudi Arabia and the United Arab Emirates. We can therefore expect Iran to double down on its support for the Houthis, especially with missiles and drones (which are essential for their ability to pressure Saudi Arabia and the UAE) as well as naval mines and various intelligence, surveillance, and reconnaissance capabilities (along with missiles and drones, essential to their ability to target shipping in the Red Sea). Recent years have seen the Houthis spread their reach across the region, notably in Iraq and Lebanon, where they deepened ties with their Axis partners, as well as in the Horn of Africa, where they have been steadily increasing their cooperation with Al-Shabaab, the local Al-Qaeda franchise. Recent events have only increased the Islamic Republic’s incentive to continue facilitating this trend.

This analysis is part of a series of publications produced by the Sana’a Center and funded by the Norwegian Ministry of Foreign Affairs under the Reimagining Yemen’s Peace in the Regional Landscape program. The series seeks to bolster peacebuilding efforts in Yemen by strategically examining the country’s security and economic ties with the broader Gulf and Red Sea region.