Why is there fighting in Yemen and what does it mean for the Iran war?

By Nadeen Ebrahim, Anna Cooban, CNN

(CNN) — The Middle East war is widening as Yemen’s Iran-backed Houthi rebels launch a spate of attacks on United States’ allies and close yet another key shipping waterway.

One of the strongest Iran-backed militias in the region, the Houthis entered the war in March, a month after Israel and the US attacked Iran, by firing missiles towards Israel. Today, the group is trading fire with Yemen’s internationally recognized government, and striking Saudi Arabia after a four-year de facto ceasefire with the kingdom.

The escalation comes while there is shaky maritime security in both the Strait of Hormuz and the Red Sea, and as Iran and the US give conflicting accounts of whether direct talks to reopen the waterway were taking place.

The latest attacks also raise the threat of an outbreak of another full-scale war in Yemen. The last war, which began in 2014, left the country facing the world’s worst humanitarian crisis.

Here’s what we know about the escalation and how it might impact the US-Iran war.

Why is there fighting in Yemen?

The war in Yemen dates back over a decade, and is primarily a conflict between the Houthi rebels and a Saudi-led coalition backing the internationally recognized government.

The Houthis belong to Yemen’s Zaidi Shia Muslim minority and are formally known as Ansar Allah – “Partisans of God.” After the Arab Spring in 2011, they seized a northern province and later the capital Sanaa, which they still hold, along with much of Yemen’s Red Sea coastline.

In the process they became part of Iran’s “Axis of Resistance,” a network of allied militant groups across the region, receiving weapons and technology.

US-allied Saudi Arabia spent seven years trying and failing to dislodge the Houthis from northern Yemen, launching a large-scale offensive against the militant group in 2015. The ensuing conflict provoked one of the world’s worst humanitarian crises.

A truce was arranged in 2022, but it never became a peace. In the same year, Yemen’s internationally recognized government, operating under the Saudi-backed Presidential Leadership Council (PLC), was established in Saudi Arabia. Riyadh has worked to prop up the government with air and naval operations, as well as limited troop deployment.

Since then, Saudi Arabia maintained an economic and air blockade against Houthi-controlled area, which the group has sought to break in recent weeks.

Why has the conflict erupted again?

Despite efforts to stay clear of the conflict, Saudi Arabia has been dragged into the war. Riyadh faced a barrage of missiles during the war and continues to face attacks from Iran-backed groups in Iraq and the Houthis in Yemen.

The Houthis have particularly risen as a menace to Saudi Arabia, targeting oil tankers and imposing a blockade on Saudi shipping in a critical maritime trade route, the Bab al-Mandeb Strait located at the base of the Red Sea.

Experts say that the Yemeni rebel group saw an opportunity to regain some of its losses during the Iran war. While its values are linked to those of Iran, they do have their own reasons to fight with Saudi Arabia.

Danny Citrinowicz, former head of the Iran branch of Israeli military intelligence, said Saudi Arabia’s conflict with the Houthis is far from over, adding that the group has appeared to cross a key threshold.

“At the heart of Riyadh’s problem is the fact that the Houthis appear to have crossed a political and military threshold: they are no longer willing to return to a status quo in which Saudi Arabia can impose or support a maritime and land blockade on areas under their control without facing retaliation,” he wrote on X.

The Houthis appear to follow Iran’s leadership logic, thinking “that time and strategic asymmetry work in their favor,” Citrinowicz said.

How are the Saudis involved?

Getting embroiled in a broader conflict would be a risky and potentially costly option for Riyadh. Over the last decade it has been focused on opening the kingdom up to foreign investment and making it the regional economic powerhouse. That in part drove its policy of détente with Iran long before the war, which led to an agreement mediated by China in 2023.

That strategy is now on life support, as Saudi Arabia finds itself in the eye of a storm. Confronting unpredictable adversaries well-versed in asymmetrical warfare from three directions is a military planner’s nightmare.

On Thursday, a Saudi official told CNN that the kingdom is bracing for a “multiple coordinated attacks” by Iraqi militias factions and Iran-backed Houthis.

The official cited “multiple intelligence reports” from Saudi Arabia, the US and regional countries indicating some Iraqi militia members, “in coordination with the Houthis” are planning to attack the Gulf nation “in the very near future” under the guidance of Iran’s Islamic Revolutionary Guard Corps (IRGC).

The official expressed alarm on Thursday, saying the reports came as Saudi Arabia was pursuing de-escalation and negotiations involving Iran appeared to be heading in the right direction.

The recent attacks – and potential ones – leave Riyadh with “an uncomfortable choice,” Citrinowicz wrote. “Escalation could lead to another open-ended war whose costs and end state are difficult to predict. But major concessions could strengthen the Houthis politically and militarily, making them an even more formidable threat in the future.”

“Saudi Arabia, in other words, is caught between deterrence and accommodation,” he said. “Neither path offers a clean strategic victory.”

On Thursday, the rebel group claimed to have carried out a “large-scale” military operation targeting Saudi troops with ballistic missiles and drones in several areas of the country.

The Houthis offered no evidence for the claim, but Reuters reported earlier that day that at least 30 Yemeni ‌government troops were killed in Houthi attacks on ⁠military camps in the provinces of Marib and Hadhramawt, citing government sources.

On Friday, the Saudi-led military coalition supporting Yemen’s internationally recognized government said 11 civilians were wounded in a Houthi attack on the southern Saudi border region of Najran.

Riyadh is, however, working to prop up its defense strategy. On Friday, Saudi Arabia, Turkey and Pakistan signed a mutual defense pact stipulating that an attack against any of them “shall be regarded as an attack against them all.”

It was a landmark deal between three nations that have all played a role in stalled diplomatic efforts to end hostilities between the US and Iran.

What are the risks?

The escalation comes as a dangerous and costly threat to both Saudi Arabia and Yemen.

For Riyadh, the revived Houthi threat is sabotaging its attempts to reroute millions of barrels of oil from the Persian Gulf to the Red Sea for export as the Strait of Hormuz remains effectively shut.

Saudi crude exports via the Bab al-Mandeb strait have at least halved since the Houthis declared a blockade on Saudi ships transiting the waterway, according to Rahul Choudhary, vice president of upstream research at Rystad Energy.

Currently, up to 1.5 million barrels are able to cross the strait every day, he told CNN earlier this week, well below the 3.2 million barrels per day seen earlier in the conflict. Before the war, Saudi Arabia produced roughly 10 million barrels per day.

Still, state-run Saudi Aramco has benefited from soaring global oil prices, reporting a $33 billion profit during the second quarter, up 33% from the same period in 2025.

But results like these “cannot hold forever,” Choudhary noted. Aramco’s figures were partly driven by oil sold from now-reduced stockpiles, he said, adding that prices — while volatile — are lower than in earlier phases of the conflict.

For Yemen, the spate of attacks risks driving the country back into full-scale civil war.

During the last round of internal fighting, the United Nations designated Yemen as the world’s worst humanitarian crisis, with more than 22 million people – three-quarters of the population – in desperate need of aid and protection.

Nine years of war had killed thousands, destroyed the economy and left tens of thousands of Yemenis living in famine, according to the UN.

Renewed fighting risks pulling the country back into the throes of an even worse humanitarian and economic crisis.

The-CNN-Wire
™ & © 2026 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.

CNN’s Tim Lister, Nic Robertson, Sophia Saifi, Hira Humayun and Sana Noor Haq contributed reporting.