Executive Summary

The 12-day war between Iran and Israel in June 2025 marked the sharpest escalation to date in the ongoing confrontation between the two states. Despite its relatively short duration, the war had a destabilizing effect on the Islamic Republic due to the success of Israel’s opening strike, the decision of the United States to join the campaign, and the damage sustained by Iran’s critical strategic systems—notably its nuclear program and long-range missile arsenal. The shock in Iran has been reflected in the name given to the war—“the Imposed War”—a term previously used to describe the eight-year conflict between Iran and Iraq in the 1980s. Just as the Iran–Iraq War shaped Iran’s security doctrine and national psyche, this recent war is also likely to leave a lasting imprint on Iran’s military-security posture, as well as its political, regional, and domestic arenas.

Since the end of the war, Iran has engaged in an ongoing process of drawing lessons from the serious gaps revealed in the Islamic Republic’s deterrence and defense capabilities. On the one hand, senior political and military officials in Tehran present the war’s outcome as evidence of an Iranian victory. In their view, Iran recovered quickly from the initial strike, conducted a simultaneous campaign against both Israel and the United States, inflicted severe damage on Israel, and ensured the regime’s survival. On the other hand, Iran has clearly acknowledged the shortcomings exposed during the war, which require at least some changes and adjustments to its security doctrine. At the same time, a sharp internal debate has emerged over the scope of necessary change. Pragmatic-reformist circles are calling for a paradigmatic shift that prioritizes addressing Iran’s urgent domestic crises through far-reaching reforms in both domestic and foreign policy, while conservative-hardline circles argue that instead of retreating from foundational principles, only limited adjustments should be made within the existing frameworks.

The most significant damage sustained by Iran during the 12-day war was to its nuclear program. The war set the program back considerably, particularly its enrichment capabilities, although residual capacities remain that could assist Iran in reconstructing the program or even breaking out to nuclear weapons. Moreover, Iran’s motivation to obtain nuclear weapons has increased in light of the war’s lessons, which exposed the failure of its deterrence; at the same time, its leadership appears apprehensive about taking steps that could trigger another strike. Although it seems that Iran currently prefers to maintain “nuclear ambiguity” regarding the capabilities it still possesses and to refrain, for now, from reconstructing the enrichment and weaponization capabilities damaged in the war, it is doubtful whether such a situation can persist for long. In parallel, Tehran continues to bar the return of International Atomic Energy Agency (IAEA) inspectors to the nuclear sites that had been attacked, and the prospect of reaching a political arrangement between Iran and the United States that would produce a nuclear agreement blocking Iran’s path to nuclear weapons appears increasingly unlikely.

At the same time, Iran has intensified its efforts to reconstruct and upgrade its military systems, particularly its missile forces and air defenses, in order to improve its readiness for a scenario of renewed fighting. These efforts include ramping back up to pre-war missile production rates, improving missile accuracy, reconstructing its air defenses, and strengthening the protection of its strategic systems. Despite the damage that the Iranian missiles inflicted on Israel during the fighting, the war demonstrated to Iran that its missile arsenal was the only system that proved itself. Tehran continues to view it as a strategic asset capable of harming Israel, wearing it down, and constraining its ability to conduct a prolonged campaign over time, given Israel’s limited interception capacity.

In the regional arena, the war further highlighted the collapse of the proxy concept, whose limitations had become increasingly evident even before the conflict—particularly after Hezbollah’s defeat in the summer of 2024 and the fall of the Assad regime in Syria. The refusal of key components of the Iranian-led “Axis of Resistance,” most notably Hezbollah, to join the war alongside Iran increased Tehran’s doubts about the effectiveness of its proxy strategy. Nonetheless, statements by senior Iranian officials—along with Iran’s continued efforts to support and assist the pro-Iranian axis, including through weapons transfers—clearly indicate that Tehran does not intend to abandon its partners in favor of a new regional strategy. Moreover, Iran continues to stress the need to preserve the military capabilities of the axis and to oppose any attempt to disarm the Shiite militias, above all Hezbollah. This dynamic is unfolding alongside Iran’s active engagement with key governments in the Arab world, including Lebanon, even as it declares that it has no intention of interfering in the internal affairs of Arab states. In addition, Iran has made sustained efforts to improve relations with its Arab neighbors, leveraging their concerns regarding its military power, their doubts about American security commitments, and their growing view of Israel as a source of regional instability.

In the domestic arena, the war demonstrated to the Iranian leadership that Israel is determined to topple the regime and even fragment Iran and undermine its territorial cohesion. Israel’s actions, however, did not destabilize the regime and, in fact, prompted the public to exhibit a significant degree of national solidarity. Nonetheless, the fundamental challenges facing the Islamic Republic are a crisis of legitimacy, a worsening economic crisis, and growing water and electricity shortages. After the war, aware of the escalating internal problems, the regime employed tactics to assuage growing public disillusionment. It sought to rally the public around symbols of Iranian nationalism, intensify political repression of its opponents, while simultaneously responding to certain public demands, such as easing the enforcement of the Islamic dress code. The war also heightened doubts about the condition of Iran’s leader, Ali Khamenei—who was forced into hiding during the war—and about the extent of his control over the regime’s decision-making machinery. These doubts, combined with his advanced age and reports of deteriorating health, have amplified the debate over the question of succession.

In sum, the war’s implications and lessons require Iran to reassess its security doctrine and policy framework. The Iranian leadership is certainly aware of the need for improvements and adjustments to its national security doctrine; yet for now, this does not appear sufficient to produce a fundamental shift in Iranian strategy. It seems that Iran prefers to make  adjustments within the existing framework by finding acceptable solutions to the gaps exposed rather than introducing major changes to its overall strategy.

Nonetheless, the new reality in Iran created by the war is characterized by instability, and it is doubtful whether the current status quo can endure for long. This is exacerbated by the growing possibility of a miscalculation between Iran and Israel that would lead to renewed clashes, or high-risk decisions by Iran on both the nuclear issue and on the regional front. Moreover, Iran’s ongoing process of drawing lessons and upgrading its weapons systems, combined with the possibility that Israel may target Iranian national infrastructure in the next round, could make a future military confrontation far more volatile, including the potential for escalation into a regional war.

There is no doubt that Iran faces significant challenges both domestically and externally, but it could also capitalize on several opportunities, including the survival of Hamas in the Gaza Strip, delays in disarming Hezbollah, the rivalry between the United States and both Russia and China, and the erosion of Israel’s international and regional standing. Conversely, Israel’s success in its ongoing campaign against Iran will depend heavily on its ability to exploit the current window of opportunity to shape a new regional reality—one that contains Iran, further weakens it, and limits its ability to leverage opportunities to regain strength.

Given this reality, Israel must act on several fronts. These include:

• Preparing for another round of fighting, particularly in scenarios involving nuclear reconstruction or a nuclear breakout;
• Preserving and further developing covert counter-proliferation capabilities to prevent or delay the reconstruction of Iran’s nuclear and missile programs, while simultaneously enhancing Israel’s own capabilities to counter the missile threat;
• Supporting international and regional efforts to promote a stable, long-term arrangement with Iran that blocks its pathway to nuclear weapons, based on an agreement that would sharply limit enrichment capabilities, allow effective and improved IAEA monitoring, and address the fissile material remaining in Iran after the war;
• Advancing understandings, even informal ones, between the United States and Iran to reduce the risk of escalation in the absence of a long-term agreement;
• Establishing a credible threat to the survival of the regime to deter Iran from steps that would bring it closer to nuclear weapons;
• Continuing enforcement measures to prevent the reconstruction of the pro-Iranian axis, led by Hezbollah;
• Encouraging regional stabilization processes, strengthening state institutions in the Arab world, and creating alternatives to Iranian influence;
• Engaging in sustained efforts to weaken the Iranian regime.