WaPo article by Ali al-Mujahed and Hugh Naylor

SANAA, Yemen Shiite insurgents stormed Yemens presidential palace Tuesday in a stunning blow to the Western-allied government that appeared pushed to the brink after months of rebel gains.
The coup-style strikes by the Houthi rebel faction believed backed by Iran marked a major setback for President Abed Rabbo Mansour Hadi, a staunch ally of the United States in the fight against al-Qaedas powerful branch in Yemen.
But it appeared the rebels would not immediately press their advantage and seek to topple the government.
A long televised statement by the rebel chief, Abdulmalik Houthi, leveled sweeping criticism against Hadi for alleged corruption and failures to unite a country beset by near nonstop unrest, a growing water shortage and a patchwork of rivalries.
He stopped short, however, of declaring a change of leadership. Instead, he demanded talks that could leave Hadi further weakened but still nominally in charge.
All options are open, said the rebel leader, warning that the offensive has no ceiling if the president does not implement plans that include granting more power to the insurgents.
It capped a day of fast-paced moves by the rebels and confusion over the fate of Hadi who government officials said was pinned down by attacks on his residence, about three miles from the palace.
Even the causes for the latest violence were interpreted in very different ways.
A statement on a Houthi-run Web site claimed the groups fighters took control of the presidential palace to avoid weapons looting amid the chaos. Government officials, meanwhile, insisted the rebels seek to drive Hadi from power and claim control of the capital.
A government collapse could send the country into full-scale civil war and raise fears of militant factions cementing control of key territory in the southwestern corner of the Arabian Peninsula.
Further instability also would reverberate far from Yemen. The group al-Qaeda in the Arabian Peninsula (AQAP) is seen one of the most active threats to the United States and its allies in the region. The group claimed a role in masterminding the deadliest attack in three days of terror in Paris earlier this month.
This is a coup. There is no other word to describe what is happening but a coup, Col. Saleh al-Jamalani, the commander of the Presidential Protection Force, told the Associated Press.
Another government official said the countrys prime minister, Khaled Bahah, had been trapped inside another palace by the Shiite fighters since Monday.
The Houthis have mounted sporadic rebellions since 2004 over perceived government discrimination in a country nearly two-thirds Sunni. Since September, the rebels have steadily moved beyond their traditional strongholds in the northern part of the country.
Their advance on the capital and beyond in recent months has badly weakened the 69-year-old Hadi, a former general who is relied upon by Washington for support in U.S. drone strikes targeting AQAP militants.
The world is very much occupied with whats going on with Iraq and Syria, but we could find ourselves facing another civil war situation in Yemen, but one where there is a power vacuum for extremists, said Riad Kahwaji, chief executive of the Dubai-based Institute for Near East and Gulf Military Analysis.
Yemens information minister, Nadia Sakkaf, wrote in an Arabic tweet that the Yemeni president is being attacked by armed militias that want to overthrow the government.
She also wrote that the presidential palace has been under attack since 3 p.m. even though political talks are still ongoing.
The Houthis rapid victories have included taking control of state-run media outlets and government buildings, notably the headquarters of the Yemeni intelligence service.
Hakim Almasmari, a Yemeni journalist, said Hadis forces are undercut because of internal tensions in the military after the president tried to oust officers seen as loyal to his predecessor, Ali Abdullah Saleh.
Saleh, a Shiite, was ousted in 2012 after an Arab Spring-inspired uprising and could exert greater influence if the current government falls.
Hadi has no loyalty with the army, and thats why you see the Houthis in power today, Almasmari said.
The showdown atmosphere has deepened since clashes Monday, when at least nine people were killed after the collapse of a cease-fire between Houthi fighters and government forces.
Irans state-run Press TV reported that Houthi rebels set up checkpoints near the presidents residence and fanned out on patrols around the capital Sanaa.
Although the Houthis have battled with al-Qaeda-linked fighters before, the potential unraveling of central authority could offer breathing room for AQAP and possible planning for attacks outside Yemen.
AQAP claimed responsibility for planning and funding the attack earlier this month at the French satirical newspaper Charlie Hebdo, which touched off days of terrorist violence that left 17 people dead.
Sunni Arab nations, including neighboring Saudi Arabia, accuse the Houthis of being a proxy for Shiite power Iran. The Houthis deny this and say they seek to root out corruption.
On Saturday, Houthi militants abducted Hadis chief of staff, Ahmed Awad bin Mubarak, who has been tasked with helping to draft a new constitution. The document includes measures that are opposed by the Houthis, who make up just less than a third of Yemens population of about 24 million.
At the United Nations, the Security Council called an emergency meeting, and Secretary General Ban Ki-moon denounced the latest fighting in Yemen.
In November, the Security Council imposed sanctions on Yemens former president Saleh and two Houthi leaders for threatening the countrys stability.