"What's a potential game-changer in all of this is not just the displacement of millions of people, but it's this huge spread of disease, starvation and inaccessibility to water, combined with an environment where radical groups are increasingly operating in the open and recruiting," said Jon Alterman, director of the Middle East Programme at the Centre for Strategic and International Studies.
The Yemen conflict, he added, could become a situation where "nobody can figure out either who started this fight or how to end it".
Saudi Arabia, a Sunni powerhouse, views Yemen's Houthi rebels as proxies of Shia Iran. The air campaign that began on March 25 is widely seen in the region as an attempt by the Saudis to counter the expanding influence of Iran, which has gained sway in Arab countries like Iraq, Syria and Lebanon.
Hadi, the internationally recognised Yemeni President, was pushed out of the capital, Sanaa, in February. He then attempted to establish an authority in Aden before being forced to flee to Riyadh, the Saudi capital, last month.
In a media briefing in Riyadh this week, a Saudi military spokesman painted a positive picture of the offensive in neighbouring Yemen, saying that Houthi militias had been isolated in Aden and groups of rebels were abandoning the fight. Saudi officials have argued that a two-week time frame is too short to judge the operation's outcome and have emphasised that they are moving carefully to avoid civilian casualties.
The Saudi-led coalition, which the United States Government supports with intelligence and weapons, consists of mostly Arab and Sunni Muslim countries, and the level of quiet coordination among their armed forces has impressed analysts. The United Arab Emirates and Jordan are believed to have joined Saudi Arabia in conducting air raids that have destroyed scores of military bases and arms depots, said Theodore Karasik, a Dubai-based analyst on Middle Eastern military issues. The Saudis also have received support from Egypt's navy in patrolling the coast of Yemen, he said.
Still, Karasik said, Houthi rebels appear to have successfully hidden from bombardment significant stores of weapons, possibly by moving them to the insurgents' mountainous northern stronghold of Saada. To destroy those arms and persuade the Houthis to halt their offensive and agree to peace talks, a ground attack would be required, he said.
"This illustrates that air power alone cannot rid enemy ground forces of their weapons and capability," Karasik said. "It makes them scatter, and it makes them hide their weapons for a later day."
Ground troops would certainly face stiff resistance from the Houthi militiamen. Seasoned guerrilla fighters, they seized southern parts of Saudi Arabia during a brief war in 2009, killing over 100 Saudi troops.
Saudi Arabia has not ruled out a ground attack, but its allies appear wary of such a move. The kingdom has asked Pakistan to commit troops to the campaign, but that country is deeply divided over participating in an operation that could anger its own Shia minority.
Though fraught with risk, continued airstrikes and a possible ground incursion may be the only choices that Saudi Arabia sees itself as having, said Imad Salamey, a Middle East expert at the Lebanese American University. He said that officials in Riyadh probably are concerned that relenting could be perceived as weakness, especially in Iran.
Saudi Arabia also considers Yemen to be its backyard, he noted. "As far as the Saudis are concerned, this is a fight for their homeland, the existence of their regime."
On Thursday, Iranian leaders issued strong condemnations of the Saudi-directed assaults. Iran's supreme leader, Ayatollah Ali Khamenei, called them a "crime and a genocide" in a televised speech.
The Yemen campaign is part of an increasingly assertive Saudi policy in the region that is driven in part by what analysts say is concern over a possible agreement on Iran's nuclear programme.
The Saudis fear such a deal could amount to US recognition of Iran's growing influence in the region.
The Saudis have said that they want to restore Hadi's government. But the president's support base - both in the splintered military and among the public - appears to be crumbling.
Many residents say they resent how Hadi and fellow exiled leaders cheer on coalition assaults from abroad as Aden residents confront heavily armed Houthi militiamen and their allies.
"He's only ever let us down," said Ali Mohammed, 28, an unemployed resident of Aden.
In other areas where anti-Houthi sentiment runs high, Hadi's stock also appears to be falling. Ahmed Othman, a politician in the southern city of Taiz, blamed Hadi for not organising military resistance against the rebels. He also expressed worry about unidentified fighters who are increasingly staging attacks on Houthi positions in the city. "The biggest concern we have now in Taiz is the absence of security," he said.
In provinces where opposition to the Houthis runs high, especially in the south, tribal forces have played an increasingly prominent role in opposing the rebels.
Farea al-Muslimi, a Yemeni analyst and visiting scholar at the Carnegie Middle East Centre, said that mounting civilian casualties from the coalition air raids have fanned public anger. So, too, have worsening shortages of food and water, he added.
He said the chaos was creating fertile ground for extremist groups like AQAP. The al-Qaeda group, which uses Yemen as a base to stage attacks in the West, has seized significant territory during the fighting, including Yemen's fifth-largest city as well as a military installation on the border with Saudi Arabia.
It may be impossible to put Yemen back together, Muslimi said.
"The days of a Yemen that could be run by one person who could be dealt with and who could take care of things are gone," he said.
That leaves the Saudis with no obvious military or diplomatic exit, he added. "This is becoming their Vietnam."
