For the United States, it was simple retaliation: rebels in Yemen had fired missiles at a US warship twice in four days, so the United States hit back, destroying rebel radar facilities with missiles.
But for the rebels and many others in Yemen, the pre-dawn strikes on Thursday were just the first public evidence of what they had long believed: that the United States had been waging an extended campaign in the country, the hidden hand behind Saudi Arabia’s punishing air war.
For the Obama administration, the missile strikes also highlighted the risks of a balancing strategy it had tried to pursue in Yemen since a bitter sectarian war engulfed the country two years ago. The United States has not formally joined the Saudi-led coalition that intervened in support of Yemen’s deposed government – and has tried to push the warring factions toward a peace deal – but it has refuelled coalition bombers, trained Saudi pilots and provided intelligence to the bombing campaign.
A year and a half of bombing – along with the deaths of thousands of Yemeni civilians – has stoked anger in Yemen not only toward the Saudis but also toward their perceived patrons in Washington.
This week’s attacks on the Mason, a US destroyer, and the Pentagon’s response, show how rapidly the United States can go from being an uneasy supporting player to an active participant in a chaotic civil war.
"The Americans have been patronising and directing the war from the very beginning," said Brig Gen Sharaf Luqman, a spokesman for the rebel alliance.
Background to conflict
Yemen's conflict started in 2014, when Shia rebels from the north, the Houthis, seized the capital, Sanaa, and sent the government into exile. They now control much of the country's north and west, along with army units loyal to former president Ali Abdullah Saleh. An international military coalition led by Saudi Arabia began a bombing campaign in March 2015 in an effort to restore the government of Abed Rabbo Mansour Hadi, the exiled president.
The Obama administration gave its immediate support to the campaign – despite scepticism that the coalition would be able to dislodge the Houthis from Sanaa – in part because it needed Saudi support for the nuclear deal it was in the process of negotiating with the kingdom's arch-enemy, Iran.
That support has come under greater scrutiny amid reports of coalition forces striking residential areas, markets, medical facilities and weddings. Last Saturday, an attack on a funeral reception in Sanaa killed more than 100 people.
The United States has also kept warships in the region to guard a sea lane through which four million barrels of oil pass each day. There, in the narrow strait at the mouth of the Red Sea, the dizzying mix of warships, cargo vessels and insurgent forces this week yielded precisely what the Obama administration had spent 18 months trying to avoid.
The US strikes, launched from rebel-held territory, came after two unsuccessful missile attacks on the Mason, the Pentagon said on Thursday, and were intended solely to protect US forces and other shipping in the Bab el-Mandeb, the strait that separates Yemen from Somalia.
More attacks would invite further retaliation, Pentagon spokesman Peter Cook said. US and allied warships will continue to patrol the strait, he said, but "we don't seek a wider role in the conflict".
Dangerous situation
That may be the case, but the United States now finds itself facing a dangerous situation in a narrow stretch of water where even small incidents run the risk of sparking a broader conflict. After the US strikes, Iran said it was dispatching two warships to the strait, presumably to support the Houthis, an indigenous Shia group with loose connections to Iran.
Saudi Arabia has portrayed the Houthis as an Iranian proxy force and has said it needed to intervene in Yemen to protect Saudi national security by preventing the rise of a belligerent militia on its southern border.
Foreign diplomats and analysts say Iran's ties to the Houthis are murkier, although Iran has provided the group with some military support. Michael Knights, a fellow at the Washington Institute for Near East Policy who studies Yemen, said that most of the arms used by the Houthi-Saleh alliance were "legacy materiel", meaning that they were in the country before the conflict started. Yemen has for a long time been awash in arms, and much of the rebels' armoury came from the Yemeni army.
But as the conflict has gone on, there has been more evidence of Iranian military support, he said. Along the Yemen-Saudi border, rebels have begun using anti-tank missiles, shoulder-launched rockets and sniper rifles of the same type used by Iranian-backed militias in Iraq and Lebanon.
Pentagon officials could not say whether it was Houthi rebels themselves who launched the missiles at the Mason (the Houthis deny doing so), or if they were fired by allied military units loyal to Yemen’s former president, Saleh, who are fighting alongside the insurgents.
But Cook said on Thursday that the main issue was the threat to US forces and that the retaliatory strikes successfully disabled the radar installations that had targeted the Mason.
“These targets were chosen based on our assessment that they were involved in missile launches in recent days, and they were struck in order to defend our ships and their crews and to protect freedom of navigation through a waterway that is vitally important to international commerce,” Cook told reporters.
Deaths of civilians
According to the
United Nations
, more than 4,000 civilians have been killed in Yemen since the bombing campaign began. Despite its extensive support for the military coalition, the Obama administration’s public position is that it is not a party to the conflict, a stance that rings hollow for many Yemenis.
“In Yemen, this is seen as a US bombing campaign,” said senator Chris Murphy, a critic of the war who led an effort in the US Senate last month to block a $1.15 billion arms deal with Saudi Arabia.
Murphy said the White House should use its leverage over the Saudis, and use the threat of dialling back some of this support, to try to rein in a campaign that has been widely condemned as reckless. "The Saudis have to know that they can't conduct this campaign without US support," he said.