Ceasefire in the 12-Day War: What Happens Next

The Israel-Iran war, ignited by Israel’s Operation Rising Lion on June 13 and escalated with the U.S. joining the fray on June 21, has reached a pivotal juncture. The ceasefire brokered by President Donald Trump on June 23 has temporarily halted the “12 Day War,” but the path forward remains fraught with tension and opportunity. Israel and the U.S. emerged as clear victors, dismantling the brunt of Iran’s nuclear and ballistic missile infrastructure while exposing the fragility of Tehran’s regional proxies. With negotiations set to resume this week between the U.S. and Iran, the stakes are high to forge a lasting peace that neutralizes Iran’s existential threat to the U.S. and to her allies in the Middle East. This essay outlines the next steps, emphasizing the decisive victory, the intelligence edge, and the stringent conditions that must define any agreement.

Israel and the U.S. achieved a resounding triumph. Operation Rising Lion, executed with precision by the Israeli Air Force, targeted Iran’s nuclear crown jewels – Natanz, Fordow, and Isfahan – decimating above-ground facilities and severely damaging underground enrichment halls. The U.S.’s Operation Midnight Hammer on June 21, deploying B-2 bombers with GBU-57 Massive Ordnance Penetrators (MOP), obliterated remaining subterranean sites, including Fordow’s deeply buried centrifuges. Intelligence assessments suggest the nuclear program was set back significantly, if not effectively gutted, with key scientists assassinated and infrastructure destroyed. Simultaneously, Israel’s strikes crippled Iran’s ballistic missile threat, hitting fixed silos, mobile launchers, factories, and killing top engineers, reducing Tehran’s retaliatory capacity to a shadow of its former self. The axis of resistance, including Hezbollah and Hamas, lies in ruins, with Iran’s proxies weakened beyond immediate threat.

Israel’s continued intelligence dominance inside Iran underscores its strategic advantage. The precision of strikes, targeting hidden sites and key personnel, reveals a robust network of assets, likely Mossad operatives and informants, penetrating Tehran’s defenses. This capability, evident in the assassination of nuclear scientists and the disruption of missile production, ensures Israel can monitor and disrupt any resurgence. The U.S., leveraging its own intelligence, complements this effort, providing a dual-layered oversight that keeps Iran on edge. This intelligence edge will be critical in enforcing future agreements, offering real-time data to preempt violations.

Negotiations resuming this week must impose stringent terms to secure long-term stability. First, Iran must disclose the location of its over 400 kg of highly enriched uranium, stockpiled at levels nearing weapons-grade, and surrender it to the U.S. for safekeeping. This move, though unverified in current reports, addresses the lingering nuclear threat, preventing Tehran from leveraging its remaining assets. Second, Iran must dismantle its uranium enrichment program entirely, a non-negotiable demand especially given its past defiance of the Joint Comprehensive Plan of Action (JCPOA). Comprehensive oversight by the U.S. and European powers, including the International Atomic Energy Agency (IAEA), must be established, with inspectors granted unfettered access to verify compliance – a stark departure from Iran’s historical opacity.

Third, Iran’s ballistic missile program, a cornerstone of its regional intimidation, must be prohibited from rebuilding. The destruction of launchers and factories during the war provides a rare window to enforce this, but Tehran’s history of clandestine development necessitates vigilant monitoring. Fourth, Israel and the U.S. must retain the right to strike Iranian targets preemptively if evidence emerges of nuclear or missile reconstitution. This mirrors the successful Lebanon mechanism enforcing the Israel-Hezbollah ceasefire since November 2024, where Israeli air power deters Hezbollah violations with minimal escalation. This preemptive strike clause, while controversial, ensures deterrence, leveraging Israel’s air superiority and U.S. firepower.

Fifth, Iran must be barred from acquiring strategic air defense systems like the Russian S-300, similar to the systems destroyed by the IAF during 2024, which could shield illicit activities from enforcement. The current degradation of Iran’s air defenses, acknowledged in recent analyses, leaves it vulnerable, but Russian or Chinese supplies could reverse this. Without this restriction, punitive measures risk becoming infeasible, as fortified defenses would complicate airstrikes. Finally, Iran must verifiably cease funding proxies like the Houthis, Iraqi militias, and Hamas, whose collapse during the war, exacerbated by Israel’s dismantling of Hezbollah, has left Tehran isolated. Financial audits and international monitoring can enforce this, cutting Iran’s lifeline to its regional network.

These demands, though perhaps harsh, are non-negotiable to eliminate Iran’s threat. The mullahs will resist, viewing them as capitulation after decades of defiance, but the war’s toll – complete and entire Israeli air-dominance over Western Iran, a crashed rial, and a shattered proxy shield – leaves little room for leverage. The establishment narrative touts this as a triumph of Western resolve, yet skeptics question Iran’s compliance, citing its history of subterfuge and the regime’s survival instinct. Internal fissures, with relative moderates like President Masoud Pezeshkian pushing diplomacy against hardliners like Saeed Jalili, may force concessions, but Khamenei’s isolation in a bunker suggests a regime teetering yet defiant.

The regional fallout supports this approach. The muted response of Russia and China reflect Iran’s isolation, while the G7’s backing of Israel’s self-defense strengthens the U.S. position. Oil price stabilization post-ceasefire signals market confidence, but Houthi threats to Red Sea shipping underscore the need to sever proxy ties. For Israel, this victory reinforces its deterrence, with Netanyahu likely to press for maximal terms. The U.S., balancing Trump’s peacemaking ambitions with domestic anti-war sentiment, must wield its diplomatic and military clout to enforce the deal.

Critically, the agreement’s success hinges on enforcement. The Lebanon model proves preemptive strikes can deter, but Iran’s underground resilience, evident in the murkiness surrounding Fordow’s survival, requires relentless intelligence and rapid response. Failure to secure these terms risks a resurgent Iran, rebuilding under new defenses, rearming proxies, and reigniting conflict. The war’s lessons – Israel’s precision, U.S. resolve, and Iran’s vulnerability – demand a bold, uncompromising peace. This is not just about victory; it’s about ensuring the Middle East’s stability, safeguarding American allies, and preventing a nuclear shadow from rising again. The clock is ticking, and negotiations this week will define the region’s future.

Good things,

Ari Sacher