Houthi militants in Yemen fired a ballistic missile on Friday toward a U.S. warship patrolling the Gulf of Aden, according to U.S. Central Command. There were no reported injuries or damage to the ship.

The attack comes one day after the U.S. and U.K. announced that they’re jointly imposing sanctions on four Houthi military officials, in an effort to deter the Iran-backed militant group from carrying out further attacks on ships in the Red Sea, a critical byway for maritime trade.

“The Houthis’ terrorist attacks on merchant vessels and their civilian crews in the Red Sea and the Gulf of Aden have disrupted international supply chains and infringed on navigational rights and freedoms,” State Department spokesperson Matthew Miller said in a statement.

The Houthis have been attacking commercial shipping vessels in the Red Sea since November, causing major disruptions to global maritime trade. The decision to announce sanctions against the group’s leaders followed two weeks after the U.S. and its allies began launching retaliatory strikes on Houthi bases.

This counteroffensive has, apparently, been unsuccessful thus far. On Jan. 25, Houthi rebels attacked two U.S.-flagged container ships carrying cargo for the U.S. Defense and State departments. No injuries were reported as a result of the attack and no damage was caused to the ships, according to the U.S. Central Command. Still, this latest act of aggression prompted the announcement of new sanctions.

So what does all of this mean? Are we at war with the Houthis? Here’s what we know:

Who are the Houthis?

The Houthis are a rebel group of Zaydi Shiites, which is a sect of Shiite Islam.

“[The Houthis] really came forward because their view was that Shia Muslims were oppressed, and that most of the political and economic power in the country was going to Sunni Muslims, who were the majority,” Gerald Feierstein, a former U.S. ambassador to Yemen, told Yahoo News.

Since 2004, the Houthis have been fighting Yemen’s internationally recognized government, which is majority Sunni. In 2014 the Houthis took over Yemen’s capital of Sanaa, and most of northern Yemen in 2016, and have managed those areas ever since.

“Economically and politically, [the Houthis] are in control of the most substantial part of the country,” said Feierstein, who is also a distinguished senior fellow for U.S. diplomacy at the Middle East Institute.

But the Houthis are not officially recognized as Yemen’s government.

What is the Houthis’ connection to Iran?

The Houthis and Iran both share an opposition to Saudi Arabia, which mostly stems from religious differences between Shiite and Sunni Muslims.

Iran is home to a majority of Shiite Muslims, and the Houthis follow a sect of Shiite Islam. Saudi Arabia’s population is largely Sunni, like the majority of Yemen’s official government. Saudi Arabia supported the Yemeni government along with a Western-backed coalition when the Houthis seized the capital from the government in 2014.

The Houthis are a part of Iran’s “Axis of Resistance,” an anti-Israel and anti-Western alliance, which includes Hamas in Gaza, and Hezbollah in Lebanon.

Have the Houthis essentially dragged the U.S. into a war?

The Biden administration insists that’s not the case.

“We are not at war with the Houthis. Actions we are taking are defensive in nature,” Pentagon deputy press secretary Sabrina Singh told reporters at a briefing last week. A spokesperson for the Department of Defense did not respond to a request for comment from Yahoo News.

“[The Houthis] have lured us into a confrontation that is likely to be long-lasting, but the U.S. has little choice,” Mick Mulroy, former deputy assistant secretary of defense for the Middle East told Yahoo News. “I do not think we are on the brink of war, at least not an all-out one. I believe the U.S. does not want to see a regional conflict escalate, but that is not entirely up to us. Iran is the common denominator behind all these actions.”

The U.S. believes the Houthis have been receiving military capabilities and intelligence from Iran in the latest Red Sea attacks, which Iran denies.

What do the Houthis say they want in all of this?

The Houthis say they are attacking commercial ships in the Red Sea to prevent them from reaching Israel, in a show of support for the Palestinians amid the ongoing war in Gaza following the Oct. 7 Hamas attack on Israel. The militant group has said its attacks won’t stop until Israel stops its bombardment in Gaza. But U.S. officials are skeptical of this stated motive.

“You have to take anything the Houthis say with a big grain of salt,” National Security Council spokesman John Kirby said at a White House briefing last week. “This idea that this is somehow about Gaza doesn’t square with the facts. Most of the ships that they’re going after have nothing to do with Israel.”

What do the Houthis really want out of all this?

“They’ve gone from being kind of nobodies, to a group that has now exploded onto the international stage virtually overnight,” Mona Yacoubian, vice president of the Middle East and North Africa Center at the U.S. Institute of Peace, told Yahoo News. “They seem to be gaining support across the board in Yemen for their stance that they have taken against Israel and by extension, the United States. Now we’re seeing that they will be perhaps touting their attacks directly on the United States as yet another element of how they seek to continue to win popular support at home and perhaps even more broadly.”

Some experts suggest that by responding to the Houthis’ attacks, the U.S. has given the group exactly what it wants: a fight.

“I do think that the Houthis wanted to provoke a U.S. response,” Feierstein told Yahoo News. “They believe that they have strengthened their domestic popular support by standing up for Palestinians, and it’s very popular with Yemenis.”

Feierstein added that she thinks the Houthis “also see this as kind of a way of burnishing their credentials as part of the Iranian ‘Axis of Resistance.’”

The Houthis’ leader, Abdul-Malik al-Houthi, seemed to confirm Feierstein’s theory in a televised statement last week, saying: “We praise God for this great blessing and great honor — for us to be in a direct confrontation with Israel and America.”

How will this end for the U.S.?

Experts say the U.S. is in a tough place with the Houthis for now, though talks of a months-long ceasefire between Israel and Hamas, mediated by Qatar, the U.S. and Egypt, could provide an opportunity to quell hostilities in the Red Sea.

“It’s a dilemma for the U.S. how to manage this,” said Feierstein. “There’s no real good strategy for the U.S. right now to try to end this except for the end of the Gaza conflict.”