Who are the Houthis and why did the US attack them?

The Houthi attacks on ships in the Red Sea following Hamas' Oct. 7 attack on Israel have riled commercial shipping and threatened to dangerously escalate heightened tensions in the Middle East.

On Thursday, the U.S. and the U.K. led a large-scale, retaliatory strike against the militants, hoping to degrade their ability to carry out attacks on vital waterways. But the group is already vowing to hit back.

Who are the Houthis, who are their allies, and what do they hope to achieve? Can the U.S. and allies contain the threat the militants pose to the region?

Officials and analysts break it down.

The Houthis are a Shiite political and military organization that took form in Yemen during the 1990s as an opposition force to the Yemeni government.

Through the years, the group became increasingly inspired by anti-American and anti-Israeli sentiments coursing through the Middle East.

In 2011, the Houthis played a major role in sparking the Yemeni Revolution, which was born out of a wave of anti-government protests and uprisings known as the Arab Spring.

The revolution forced a transfer of power, but the Houthis were displeased with the newly installed leaders and in 2014 the group took control of Sanaa, the Yemeni capital, prompting an ongoing civil war that has ravaged the country.

A Saudi-led coalition intervened in the conflict with the stated goal of restoring the former rulers to power, but Yemen remains fractured. The Houthis retain control of Sanaa and large swaths of territory in western Yemen, but the group has failed to accomplish its aim of becoming the country's internationally recognized government.

The Yemeni civil war entered a cooling period in 2022, when the United Nations brokered a ceasefire between the warring parties.