After the failure of negotiations with Iranian interlocutors in Pakistan, the United States has initiated a naval blockade on Iranian ports, effective at 10 a.m. EDT on Monday, April 13.
Below, Hudson Institute Senior Fellow Can Kasapoğlu outlines the state of play as the blockade takes effect—and what comes next.
Why the Negotiations Failed
As representatives from Washington and Tehran began discussions in Islamabad, Pakistan, last weekend, the gap between Iran’s reported ten-point framework and the Trump administration’s fifteen-point proposal was not merely wide, but structurally unbridgeable from the outset.
In Islamabad, Iran’s diplomatic posture was maximalist, and anchored in the ruling regime’s desire to secure its survival. Iran’s program was marked by inconsistencies between its English and Farsi renditions. Tehran sought the full lifting of primary and secondary sanctions, the release of its frozen financial assets, and preservation of its strategic leverage over the Strait of Hormuz, a vital artery of the global economy. Iranian negotiators also demanded a US military withdrawal from the Middle East and a binding, irreversible guarantee to end all combat operations against Iran. Critically, Tehran extended this demand to its network of proxies, including Hezbollah.
More consequentially, Tehran insisted on continuing to enrich uranium, a position that would allow it to pursue ambitions for military-grade nuclear capabilities. Notably absent from Iran’s negotiating position was any willingness to accept any constraints on the country’s ballistic-missile or drone-warfare capabilities.
To be sure, Tehran’s ten-point framework, crafted by a regime intent on retaining power, may have been as much a propaganda document as a good-faith expression of its negotiating position. Nonetheless, the ten-point program demonstrated the chasm between the regime’s public statements and facts on the ground.
By contrast, according to press reporting, the fifteen-point proposal put forward by the administration of US President Donald Trump—and reportedly transmitted via Pakistan—reflected a framework for coercive rollback. It called for the removal of Iran’s stockpiles of highly enriched uranium, a halt to its enrichment activities, restrictions on its development of ballistic missiles, and the termination of Tehran’s financial support for its regional partners and proxies.
In this context, the prospect of a nuclear Iran in control of the Strait of Hormuz proved more difficult for Washington and its regional allies to accept than the risk of further clashes, however disruptive they might be. The tipping point between a renewed round of fighting and a more durable ceasefire was determined not only by the gulf between US and Iranian negotiating positions, but also by Washington’s assessment of the mounting risk of broader regional destabilization against the costs of continued war.
Critical third-party dynamics also informed the Trump administration’s approach to negotiations. Foremost among these was Israel’s fight against Hezbollah in Lebanon. The Israel Defense Forces (IDF) have treated its campaign against Iran’s Lebanese proxy as an autonomous threat vector, rather than as a subsidiary front in the broader fight between the United States and Iran. Hezbollah has offered no reliable commitment to a ceasefire, and has maintained its wartime footing. As a result, even if Washington and Tehran had edged toward a temporary accommodation, combat operations in Lebanon would have remained a significant complicating factor.
The Iranian Regime Is Wounded but Still Dangerous
While the Islamic Republic has not been defeated, it has been degraded. Yet Tehran still retains a critical military edge. The Iranian regime’s threat profile rests on both its residual capabilities and its political will. Its operations are guided by the still-intact doctrinal order of battle and discipline of Iran’s Islamic Revolutionary Guard Corps (IRGC), which is fighting from a position of weakness.
Although available data indicate that the frequency of Iran’s missile salvos has declined, largely because of sustained US and Israeli efforts to hunt and neutralize its ballistic missile launchers, Tehran’s strike complex has not been totally dismantled. More important, Iran’s reduced launch volume has been offset by a qualitative shift toward attacking higher-value assets. Tehran’s targeting pattern reflects a deliberate and disruptive concept of operations (CONOPS).
Iran has systematically attacked high-value targets, including an E-3 Sentry Airborne Early Warning and Control (AEW&C) aircraft, several KC-135 tankers, and key components of regional sensor networks. Iranian drones struck two AN/GSC-52B satellite terminals at the headquarters of the Fifth Fleet in Bahrain. Satellite images also confirm repeated strikes on communications equipment at Camp Arifjan and Ali Al Salem Air Base in Kuwait. Other Iranian strikes degraded US early warning systems, including the AN/TPY-2 sensors supporting THAAD batteries at Muwaffaq Salti Air Base in Jordan, al-Ruwais Air Base in the United Arab Emirates, and Prince Sultan Air Base in Saudi Arabia, as well as the AN/FPS-132 radar at Al Udeid Air Base in Qatar.
These targets function as strategic enablers for the US military. They support sustained sortie generation for US air operations and form the sensor backbone of regional air and missile defenses. Damage to these reverberates across the entire battlespace. Even with a reduced rate of missile salvos, Iran—possibly with support from Russia and China—is now targeting high-cost, high-impact nodes within US Central Command’s (CENTCOM) battle network.
Tehran is applying this same military-economic logic to energy infrastructure targets. In late March, Iranian strikes reportedly disrupted 17 percent of Qatar’s liquid natural gas (LNG) exports, resulting in an estimated $20 billion loss. This campaign affected not only the Gulf Arab states but also placed added pressure on European and Asian energy markets.
Because of the accumulative effects of US and Israeli strikes, Iran is indeed launching fewer weapons. However, those it does launch are producing more precise and high-impact strategic effects. Operationally, this generates a highly disruptive threat calculus in which lower salvo rates can still inflict disproportionate damage on high-value military and economic targets.
Moreover, multiple open-source indicators suggest that China may be preparing to transfer tactical air-defense systems to Iran, including high-end man-portable air defense systems (MANPADS). Recent air engagements—such as Iran’s downing of a US F-15 fighter jet and reported attempts to down an F-35—underscore an evolving threat environment. While joint US and Israel suppression of enemy air defense (SEAD) operations have largely degraded Iran’s high- and medium-altitude air defenses, as well as much of its radar architecture, Tehran retains a residual layer of unconventional systems.
These systems, characterized by high mobility, agile behaviors, and minimal signatures, include MANPADS, mobile and pop-up air defenses, and air-defense drones known as the “358,” which are equipped with infrared and electro-optical targeting features. Although these assets do not generate broad-area denial, they impose localized and acute risk. In a battlespace as vast Iranian airspace, they present persistent, hard-to-predict threats to US combat aircraft.
The implications of this dynamic extend beyond strike operations. MANPADS and air-defense drones cannot decisively hamper US airpower, but they can achieve a few lucky shots, which would be invaluable to the regime’s political warfare goals. Although last week’s high-profile combat search and rescue mission for the crew of the F-15 downed over Iran demonstrated unmatched capability, any such operation conducted deep within hostile territory entails significant risk.
Iran Is Weakened Yet Radicalized
Beyond the military dimension, consequential political shifts are unfolding within Iran. The succession process following the death of Iran’s former supreme leader, Ali Khamenei, has produced an opaque picture of the fragile leadership now in control.
Mojtaba Khamenei, Ali’s son, has ostensibly assumed the reins of power. Yet the accession of Khamenei fils marks a departure from the foundational norms of Iran’s fundamentalist regime, which has long viewed hereditary succession with suspicion. Moreover, the younger Khamenei took power with inadequate clerical credentials and after a drumhead election that provided only a thin veneer of legitimacy. Since the strike that killed his father, Mojtaba has not made a public appearance and may be suffering from serious health complications stemming from his proximity to that same attack. His disappearance has compounded uncertainty at the apex of Iran’s political power.
In contrast to the IRGC’s hardline statements on the war, Iran’s president, Masoud Pezeshkian, has adopted a more conciliatory diplomatic tone. This moderation, however, appears largely cosmetic. Control over the Islamic Republic’s core coercive instruments lies outside the presidency. Past patterns are instructive: even when civilian leadership have signaled an intent to de-escalate with regional actors, the IRGC has continued to carry out long-range strikes.
Generational changes within the IRGC presents deeper structural issues. Veterans of the Iran-Iraq War are gradually being replaced by a more hawkish cohort. This emerging elite pairs a more hardline outlook with limited political maturity. Moreover, the IRGC senior levels lack a credible moderating voice. The forces new commandant, General Ahmad Vahidi—long associated with militant networks and sought by Interpol on terrorism charges—embodies the regime’s prevailing stance.
Leaked intelligence suggests that Vahidi reacted sharply to reports that Iranian negotiators in Pakistan had engaged cordially with their US counterparts, including by shaking their hands. General Vahidi reportedly viewed these basic diplomatic gestures as unacceptable. Internal developments within Iran also carry problematic signals, as the regime has continued to execute large numbers of young protestors.
Taken together, these dynamics place what remains of Iran’s leadership in an increasingly hostile trajectory. A conflict that ends prematurely risks producing a regime that is politically radicalized yet retains sufficient military capability to satisfy a heightened desire for retaliation, including through asymmetric and terrorist methods.
Still more dangerous would be an IRGC-dominated regime that retains any hope of nuclearization. Access to previously enriched uranium stocks—potentially recoverable from stockpiles buried under tons of rubble—would almost certainly prompt the region to pursue nuclear weapons as a perceived guarantor of its own security.
What Happens Next?
At 10:00 a.m. EDT on Monday, April 13, a US military blockade of Iranian ports took effect. According to CENTCOM, the blockade will be applied impartially to vessels entering or departing Iranian ports and coastal areas, including all Iranian terminals along the Arabian Gulf and the Gulf of Oman. Maritime traffic bound for non-Iranian ports will not be interdicted.
As articulated by President Donald Trump, the stated objective of the blockade is to compel Tehran to reverse its de facto restriction of maritime transit through the Strait of Hormuz, a passage that accounts for approximately twenty percent of global oil flows. Given Iran’s reliance on the strait and the regime’s dependence on hydrocarbon revenues, a successful blockade could significantly intensify pressure on Iran’s leadership.
The move, however, carries clear escalation risks. The IRGC retains several options for responding to the blockade. Most prominently, it could activate its proxy in Yemen, the Houthis, to trigger a parallel chokepoint crisis at the Bab el-Mandeb, disrupting maritime traffic between the Red Sea and the Gulf of Aden. Such an action would likely produce a secondary shock to global energy markets.
Iran also continues to possess anti-ship missile systems and naval-drone capabilities that threaten US naval assets. Defending against these threats could potentially force US planners to expand the American maritime footprint in the region. Additionally, as previous editions of this report have warned, the IRGC could widen the battlespace by targeting water desalination infrastructure in the Gulf Arab states, thereby introducing a major civilian vulnerability into the escalation ladder.
Despite these operational risks, the dangers associated with a naval blockade remain far below those posed by any potential ground campaign against Iran, which would entail far higher costs and uncertainties. At present, the blockade represents a medium-risk, high-reward option for the United States.