Yemen’s government forces have carried out air attacks against the Iran-backed Houthis to repel their advances, as the rebel group has been gaining ground in government-held positions in the past week.

The focus of the fighting is now shifting to the region of Marib – the government’s last remaining stronghold in the north and a major oil and gas hub. Should the Houthis gain control of it, it could decisively turn the tide of the war in their favour, say analysts.

Heated battles are also taking place in western Taiz, on the western coast, where reports suggest government forces, supported by Saudi Arabia, are now on the counteroffensive after losing some ground there last week. A video released on Monday by the Yemeni army purports to show Houthi positions and vehicles being bombed there.

Trapped in the middle are the civilians. The International Organization for Migration (IOM) has reported that more than 85,000 have been forced to flee their homes since the beginning of September. More than 2,000 have fled into Djibouti’s northern shores.

So why does Marib matter?

It is the last remaining stronghold of anti-Houthi forces in northern Yemen. A Houthi expansion there would threaten government presence and weaken its leverage in the north.

Marib also hosts the country’s largest gas and oil fields, meaning that whoever controls it holds some of Yemen’s most important energy infrastructure and a potentially crucial source of revenue.

“Dominating Marib’s oil and gas resources has been a Houthi goal for more than a decade. Without facing a crushing defeat in Marib, they would keep fighting to achieve that goal,” Saddam al-Huraibi, a Yemeni political commentator, told Al Jazeera. Should they gain control of it, the group could earn great leverage to negotiate favourable terms in any future mediation effort.

A Houthi capture of Marib would be a “watershed moment” in terms of the country’s internal dynamics, said Adam Baron, a fellow at the Future Security Program of the New America think tank. Still, he said, it will be a tough fight as government forces will see this battle as an existential war. “Losing Marib would be an absolute crushing defeat” for the forces of Yemen’s internationally recognised government, he added.

Marib is also geographically significant because it lies on the easiest road that runs from northern Yemen to Shabwa Governorate in the south – a seafront on the Gulf of Aden and the Arabian Sea – and al-Mahra Governorate.

The optics of a win in Marib would also be a powerful propaganda tool for the Houthis, helping them convince many Yemenis that the group is on a roll militarily and is poised for even greater victories, said Nabil Hetari, a Yemeni writer and human rights activist.

There is also a humanitarian dimension. Over the years, the city has been welcoming displaced people from areas which have fallen under Houthi control since the fall of the capital Sanaa in 2014. According to IOM figures from 2023, Yemen recorded nearly 2.8 million internally displaced people, more than half of whom (58 percent) are in Marib.

“All the parties involved in the battle are focused on Marib as a potential decider in the nature of their exit from this war,” said Hetari.

And why does Taiz matter?

The strategic importance of Taiz lies in its geography.

The governorate forms a bridge between the Houthi-held north and the government-held south and the Red Sea coast. Thus, whoever controls it gains the upper hand in the movement of weapons and supplies between the interior and the southern port city of Aden.

Taiz also carries considerable political weight. One of Yemen’s largest population centres, the city became an important centre of resistance to the Houthis after they seized Sanaa in 2014 and has endured years of fighting and restrictions on access. A major Houthi breakthrough there would therefore carry symbolic significance far beyond the territory captured.

Its western coast also stretches towards Mocha, a historic town that the Houthis captured last week, and towards the Bab al-Mandeb strait, a chokepoint connecting the Red Sea to the Gulf of Aden.

Bab al-Mandeb is one of the world’s most important shipping routes. The 20km- (12-mile-)wide waterway lies between Yemen and Djibouti, connecting Europe to Asia. Before fighting resumed, about 12 percent of global trade passed through it. In recent days, the Houthis have grabbed most of Yemen’s Red Sea coast, including Mayyun (Perim) Island, which lies in the strait.

“The Houthis seek to move closer to this vital waterway to threaten maritime traffic. Such a move aims to keep the Strait of Hormuz and Bab al-Mandeb under the influence of Iran and use them as leverage against regional and international powers,” said Fuad Mussed, a Yemeni analyst and author. “This is a strategy Tehran has been pursuing for years.”

This is a serious concern for Saudi Arabia, which has been relying on the Red Sea route to export its oil, bypassing the Strait of Hormuz.