- Iran-backed Houthi rebels in Yemen have been launching attacks on shipping in the Red Sea.
- The rebels said the missile and drone assaults are in protest to Israel's bombings in Gaza.
- The Houthis are not new to the scene: they're on one side of Yemen's decade-long civil war.
For weeks, shipping vessels around the Red Sea have been harassed by Yemeni militants called the Houthis, disrupting one of the world's most important trade routes.
A military coalition led by the US has blasted down drone and missile attacks from the Iran-backed rebels.
Now the situation is heating up. The US and UK bombed over a dozen Houthi sites in Yemen on Thursday night in retaliation for the militant group's ongoing attacks. The group has since vowed revenge for the deadly strikes.
Here's the history of the Houthi rebels and how they fit into the broader Middle East conflict.
Who are the Houthis?
The Houthis — named after their founder Abdul-Malik al-Houthi — are an Iran-backed Yemeni militant group that has been battling the country's US-backed government since the 1990s.
The rebels, who belong to a Shiite branch of Islam, control parts of Yemen and lead one side of the civil war that has consumed the country for nearly a decade, killing tens of thousands of people.
The Iranian allies have previously launched attacks against its neighbors, including Saudi Arabia after the powerful Gulf state intervened in the Yemeni civil war, according to the Center for Strategic and International Studies.
A core part of the Houthis' ideology is an opposition to US imperialism and Israel colored with religious language and antisemitism. Their slogan — recently posted on X by a member of the Houthi's political bureau — translates to: "God is Great, Death to America, Death to Israel, Curse the Jews, Victory to Islam."
Why are the Houthis attacking ships in the Red Sea?
The Houthis have supported Hamas since it first attacked Israel in October and killed hundreds of civilians. Israel has responded with a fierce, months-long bombing campaign in the Gaza Strip where Hamas holds power.
Israel's military has said it is taking steps to reduce civilian casualties, but there has been an international outcry over the scale of destruction in Gaza; the Hamas-led Gazan Health Authority says 23,000 people have died in the Israeli bombings and ground assaults.
The Houthis say they've attacked dozens of international ships that passed through the Suez Canal and into the Red Sea as retaliation for the Israeli bombings.
The rebels claim the vessels are on their way to help Israel, though many of the commercial ships under attack were not bound for Israeli shores.
The Houthis have attacked ships using anti-ship missiles, unmanned aerial drones, and small boats containing armed militant fighters.
Yemen is located on the coast of the Red Sea, giving the Houthis prime access to the crucial route.
How could the Houthis' attacks affect the rest of the world?
Any disruptions to that traffic flow could seriously affect the global economy, Business Insider previously reported.
US Secretary of State Antony Blinken told reporters at a press conference this week that the Houthis' attacks on international shipping are "a threat to everyone."
"These attacks are having a real effect on the prices that people have to pay for food, for medicine, for energy," he said. "Ships have to get diverted to other places, insurance rates go up, and the basic principle of freedom of navigation is what's at stake."
In December, the US announced the launch of Operation Prosperity Guardian, an international coalition of naval assets to protect commercial shipping.
US ships have been shot down dozens of Houthi missiles and drones and repelled their attacks. But some have gotten through.
A Maersk ship was struck by a missile in late December; the shipping giant then announced it would pause sending ships through the area.