Just weeks after the United States and Iran signed a preliminary agreement to end their war, fighting has reignited with an intensity that has surprised even close observers of the conflict. Here's a full explainer on how this second phase started, why it's raging, and what makes it different from the war's original outbreak.
How the Original War Began
The conflict traces back to February 28, 2026, when the United States and Israel launched joint airstrikes on Iran, targeting the country's nuclear facilities, military infrastructure, and leadership. Trump described the war's goals as destroying Iran's ballistic missile capabilities, eliminating its navy, preventing it from ever acquiring a nuclear weapon, and severing its support for regional proxy forces — while also calling for regime change and encouraging Iranians to seize control of their own government. The opening strikes killed Iran's Supreme Leader Ayatollah Ali Khamenei, triggering a wave of retaliatory missile and drone attacks from Iran across the Middle East. After roughly 40 days of sustained combat, a ceasefire took effect on April 8, 2026.
The Fragile Truce
In June, the U.S. and Iran announced a Memorandum of Understanding establishing a 60-day framework for negotiations over Iran's nuclear program and regional security. The truce was shaky from the start, defined by a recurring pattern: Iran would strike commercial shipping, the U.S. would respond with limited retaliatory strikes, and Iran would then hit Gulf allies of the U.S., including Bahrain and Kuwait — a contained cycle of tit-for-tat escalation that, while tense, remained short of full-scale renewed war.
The Spark: A Cargo Ship Attack
That pattern broke roughly a week after the ceasefire and MOU were signed. On June 25, an Iranian drone struck a cargo ship transiting the Strait of Hormuz — causing no casualties or major damage, but setting off a chain of hostilities that would put the two countries back on a path toward all-out war within a month of agreeing to stop fighting. The situation escalated further after the funeral for Ayatollah Khamenei began on July 4, with mourning crowds calling for revenge against President Trump. Days later, on July 6-7, Iran attacked three commercial ships in the Strait of Hormuz, and the U.S. responded with a wave of strikes targeting air defense systems and related military infrastructure.
What Broke the Contained Pattern
The relatively contained cycle of limited retaliation ended definitively when the U.S. struck Iran for a second consecutive night in what it called "offensive" strikes, prompting Iran to retaliate with attacks on Jordan — expanding the conflict's geographic scope beyond the more limited tit-for-tat exchanges that had defined the weeks prior. At the heart of the dispute is control over the Strait of Hormuz itself: since the MOU's conclusion, Iran has repeatedly threatened and attacked ships passing through the waterway in an apparent effort to coerce commercial vessels and the international community into following routes and protocols set by Tehran — an arrangement that would let Iran effectively control the strait and collect fees on passing ships, testing the limits of what the MOU actually permits.
What's Genuinely Different This Time
Analysts told Al Jazeera the conflict has evolved from the original war's broad, sustained air campaign across Iranian cities into something more targeted: sustained combat, but with more limited areas of engagement, focused heavily around the Strait of Hormuz and the Gulf states hosting American forces. Oil prices have spiked and markets have swung sharply as Tehran has moved to shut down the strait — described by observers as the "global energy kill switch" and the single biggest flashpoint of the entire conflict. When Trump declared at the July 8 NATO summit that he believed the ceasefire was "over," Iran's new Supreme Leader, Mojtaba Khamenei, responded pointedly: "Revenge is the will of the nation."
Regional Spillover
The renewed fighting has drawn in a wider set of countries than the original war's opening phase. Air raid sirens have sounded across multiple Gulf nations as both sides have launched expansive attacks, with strikes and interceptions reported in Bahrain, Kuwait, Jordan, Qatar, and the UAE. Pakistan, which shares a 900-kilometer border with Iran and maintains close ties to both Tehran and Riyadh, has played a central mediating role throughout the broader conflict — having brokered the original two-week ceasefire back in April and hosted the subsequent Islamabad Talks — while simultaneously navigating its own separate conflict with Afghanistan and domestic protests tied to an energy crisis linked to the war.
A Strategy Still Taking Shape
According to reporting on the Trump administration's approach, the latest phase of the U.S. military campaign has a new focus — centered squarely on protecting shipping and degrading Iran's ability to threaten the strait — but not necessarily a clearer overall strategy than the war's original phase. That ambiguity mirrors a broader debate over the war's underlying rationale that has persisted since February: while U.S. and Israeli officials have consistently framed the conflict as a preemptive war of self-defense against Iran's nuclear program, critics have noted that Iran's highly enriched uranium stockpile is now assessed as posing a riskier proliferation scenario than it did before the war began — closer to weapons-capable levels than the diplomatic settlement that had been under negotiation in Geneva just before the initial February strikes.
What's Next
With the underlying dispute over control of the Strait of Hormuz still unresolved, Iran's new leadership publicly vowing revenge, and fighting having already expanded to strikes across at least six Gulf states, this second phase of the war shows no clear sign of returning to the more contained, limited-retaliation pattern that briefly held after the original April ceasefire. Whether renewed diplomatic efforts — including ongoing mediation attempts by Pakistan and Qatar — can pull the conflict back from full-scale war, or whether the current trajectory of escalation continues, remains the central open question shaping the region's near-term future.