Airstrikes on a funeral in Yemen on Sunday have inflamed local opinion, and Washington's support for Saudi Arabia's campaign against Houthi rebels has implicated the United States in civilian deaths, according to human rights groups.
But there's another potential side effect: It may have prompted the rebels to turn their weapons against US forces.
The strikes killed more than 140 people and wounded hundreds more. Saudi officials have denied they carried out the attack, but two US defence officials, who spoke on the condition of anonymity because of the sensitivity of the matter, said there is little reason to believe that.
The attacks on a funeral for a Houthi rebel commander in Yemen's capital city of Sanaa are the latest in a long line of strikes that have killed more than 4000 civilians since the Saudis began launching airstrikes against the rebels in March last year.
Within hours of the airstrike on the funeral, a missile was launched from Houthi-controlled territory over Yemen's northern border into Saudi Arabia and two more were fired at the USS Mason, a Navy destroyer, and the USS Ponce, an amphibious staging base, that were in the Red Sea.
Another was fired at the USS Mason yesterday.
The ships took undisclosed defensive measures.
On Wednesday, Navy Captain Jeff Davis, a Pentagon spokesman, said: "Anybody who fires on US Navy ships does so at peril to themselves." Pentagon Press Secretary Peter Cook yesterday said: "Those who threaten our forces should know that US commanders retain the right to defend their ships, and we will respond to this threat at the appropriate time and in the appropriate manner."
The Houthis took credit for firing the missile north into Saudi Arabia and firing at one of the US ships.
The Obama Administration said after the strikes on the funeral that it had "initiated an immediate review of our already significantly reduced support" to the Saudis and are "prepared to adjust our support so as to better align with US principles, values and interests, including achieving an immediate and durable end to Yemen's tragic conflict".
A spokesman for US Central Command, Army Major Josh Jacques, said on Wednesday that at this point, the military has not been directed to change any support in regard to Saudi Arabia. Refuelling operations are carried out at the request of the Saudis, most recently on Monday, outside Yemeni air space, he said.
The US military previously provided the Saudis with other forms of support, including intelligence that could be developed into targets in Yemen. However, the Pentagon has scaled back a Joint Combined Planning Cell working with the Saudis from about 45 US service members to five.
Since June, support outside of refuelling operations has been "minimal", and no longer includes providing targeting information or intelligence, a defence official said.
Chris Harmer, a retired Navy officer and analyst with the Institute for the Study of War, said that the strikes on the funeral have again put Washington in the spotlight as the "chief protector" of the Saudi kingdom, despite the latter's ugly record on human rights. It's unlikely the US will be willing to entirely give up that relationship, however, because the Saudis help counter the regional influence of Iran, which smuggles weapons to the Houthis, Harmer said.
US Special Operations troops were forced to leave al-Anad air base in southwestern Yemen in March last year as security deteriorated in the country following the fall of the Yemeni Government. Within two months of the Saudi airstrikes, however, the US again deployed a small number of Special Operations troops to Yemen to fight al-Qaeda in the Arabian Peninsula (AQAP), considered among the most dangerous of the group's affiliates.
The US extended that deployment in June, with defence officials saying they also were sending a small team of Special Operations troops to the Yemeni city of Mukalla after it was recaptured from AQAP by Emirati and Yemeni government forces.
A US defence official, speaking on the condition of anonymity in order to discuss special operations, said Tuesday that it is unlikely the counterterrorism mission in Yemen will be affected by the ongoing review of military support the Saudis receive from the United States.
"I think everyone understands the very important mission at hand," the official said. "I don't think this situation with Saudi Arabia is going to affect our ability to directly go after the enemies of our nation."