A campaign of airstrikes and rumors of a ground invasion intended to undermine Yemen's Houthi movement may have already begun to have the opposite effect, as images of civilian deaths and a decades-old hostility to foreign intervention threaten to grip public opinion.
The strikes, launched by a Saudi Arabia-led coalition of Arab governments, began to hammer targets across the country on Wednesday, amid Saudi fears that Houthi militias were on the verge of overrunning Aden. The southern port city had become a refuge for the country's most recent elected president Abd Rabbu Mansour Hadi, who is backed by the Saudis.
"The bombardment was relentless," Hisham Omeisy, a Sanaa-based political analyst, told VICE News. "It wasn't one or two air strikes, it was continuous, unceasing for almost four hours. It didn't sound like a strategic strike, it sounded like an all-out war. The earth was shaking."
"People in Sanaa right now will sympathize with the Houthis against the foreign incursion by Saudi Arabia, even if they are anti-Houthi," he said.
The Houthis, adherents to the Zaidi sect of Shia Islam, swept into Sanaa in September, and deposed then-president Hadi in January. Hadi fled to Aden, where he remained until this week.
The strikes were backed by the US, which has offered logistical and intelligence support. Saudi Arabia is opposed to the Houthis, who they believe to be proxies for Iran, their main regional foe.
"I tend to think that the Iran card has been overplayed a bit," Elisabeth Kendall, a Yemen expert and fellow at Pembroke College Oxford, told VICE News. "The Iranians haven't helped matters by claiming a hand in the Houthi success. We know beyond any reasonable doubt that Iran has been helping the Houthis — but do they have a control? It is very unlikely."
Hadi on Tuesday called on the UN to back a military intervention in the country, "to protect Yemen and to deter Houthi aggression." By Thursday, he had fled to neighboring Oman, while forces loyal to him battled Houthis and their allies on the outskirts of Aden.
"Ordinary Yemenis — already hit hard by years of conflict — are now enduring the effects of this escalation," the International Committee of the Red Cross said in a statement.
Three Egyptian officials claimed, in anonymous remarks reported by the AP, that Egypt and Saudi Arabia are planning to invade Yemen in a pincer attack designed to crush the Houthis, who until yesterday stood on the brink of overrunning one of the few remaining cities to hold out against their advance.
There was no official confirmation of the reports. A statement from Egypt's presidency referred only to "the participation of units from the Egyptian Navy and Air Force" in a plan to "restore stability and legitimacy in Yemen."
"The Saudis and the Egyptians definitely want people to think that they're planning a ground invasion," Adam Baron, a visiting fellow at the European Council on Foreign Relations, told VICE News. "But it's hard to believe that they would actually do that because it would really be very high risk for them to put boots on the ground in Yemen."
Any army fighting the battle-hardened Houthis in the mountainous terrain of northern Yemen would likely fare very badly, Baron said. An Egyptian army which sought to intervene in Yemen during the 1960s met stiff resistance, and withdrew defeated.
Fuel on the Fire
The Houthis have formed an alliance of convenience with another former president, Ali Abdullah Saleh, who was unseated following mass protests in the early, hopeful days of the Arab Spring.
Forces loyal to Saleh have been battling Hadi's beleaguered troops around Aden. Saleh, while president, was backed by Saudi Arabia, but his forces have now been declared to be targets of the Saudi-led campaign.
The Houthis, who have their origins in a youth movement which sprung up in northern Yemen during the early 1990s, took power because they believed their interests had not been recognized in a national dialogue designed to produce a new constitution.
Kendall believes that they were far from alone in objecting to that process. She found that 98.7 percent of Yemenis in an eastern region which she studies were also opposed to the proposals.
Saudi state media have stated that the objective of the bombing campaign is to force the Houthis into a negotiated power-sharing settlement, which is likely to have echoes of the constitutional settlement to which the Houthis objected — or to be even less advantageous for them.
Kendall thinks that the current crisis has its roots in the failure to find an inclusive compromise in the wake of the 2011 uprising.
"Without transitional justice, there cannot be any transition," she said. "And for that transition to happen, you need properly inclusive deals which break the backs of the old elites. Wheeling out the same old players all the time was never going to work." She argues that the air strikes risk inflaming the escalating conflict further.
"We might consider resorting to arms as a last resort, but really it's an everyday reality in Yemen. When you are threatened from the outside like that, it pulls people together, rather than making them pull back and head to the negotiating table," she added.
"The Houthis hate foreign intervention — this has been one of their most powerful messages. It resonates well in Yemen that they are the ones who stand up to foreign intervention."
Nonetheless, Baron believes that Houthis now find themselves in a squeeze. "The Houthis are in a very difficult position and it's hard to see how they will exit this while saving face," he said.
"They're going to have to withdraw their forces from the South of the country in order to shore up Sanaa and their bases in the North. The Saudi idea is to force them to leave them with no choice except to back down."
"There's a potential that this could lead to some sort of negotiated settlement. The other option is that you have two sides that are trapped in a conflict that neither side knows how to get out of," he added.
Follow Tom Dale on Twitter: @tom_d_