Five Arab countries have accused Qatar of supporting terrorism and cut diplomatic ties with the Persian Gulf nation, triggering the region's worst diplomatic crisis in years.
Saudi Arabia, the United Arab Emirates, Egypt, Bahrain and the internationally backed government in Yemen halted all land, air and sea traffic to Qatar on Monday and ejected its diplomats. All but Egypt, which has thousands of people working in Qatar, ordered their citizens to leave the country.
Qatari diplomats were given 48 hours to leave their posts in Bahrain and Egypt, while Qatari citizens had two weeks to depart Bahrain, Saudi Arabia and the United Arab Emirates. Al Jazeera news agency, which is based in Doha, Qatar's capital, was forced to shut down its office in Saudi Arabia on Monday.
Qatar was also expelled from the Saudi-led coalition fighting Houthi rebels in Yemen.
While Persian Gulf countries have pulled their ambassadors from Doha in the past and even blocked Qatar's borders, the coordinated blockade was "shockingly aggressive," said Saeed Wahabi, a political analyst based in the United Arab Emirates.
"They are kind of putting them under sanctions," he said. "I can't think of some time when a gulf country went under a siege or sanctions."
Qatar, a country of 2.4 million, shares a border with Saudi Arabia and imports almost all of its food, about 40% directly from the kingdom. Qataris who often cross the border to shop in Saudi Arabia will be blocked, and several airlines have suspended service.
Tensions have been building for years as Qatar expanded its reach through Al Jazeera, conducted business with Iran, condoned fundraising for militant Islamist groups and harbored leaders of the Muslim Brotherhood, which is banned by other Arab nations.
"Qatar was able over the past 10 years or so to punch above its weight because of its investments and these media outlets, which support Qatari foreign policy," said H.A. Hellyer, a Cairo-based nonresident fellow at the Atlantic Council's Rafik Hariri Center for the Middle East. "That is going to be reduced tremendously."
Qatari officials, who have denied accusations that they fund the Muslim Brotherhood and other extremist groups, showed no immediate sign of backing down. "The state of Qatar has been subjected to a campaign of lies that have reached the point of complete fabrication," its Foreign Ministry said in a statement.
But Hellyer said that economic pressure will eventually force Qatar to make concessions, particularly to Saudi Arabia. "I don't think Doha will hold out too long," he said. "It doesn't have too many places to go when it comes to airspace or a land corridor. It's surrounded."
Saudi officials attributed the decision to cut diplomatic ties to Qatar's "embrace of various terrorist and sectarian groups aimed at destabilizing the region." Wahabi said Qatar has been unwilling to enforce restrictions on terrorism financing and to partner with the U.S. on counter-terrorism the way Saudi Arabia has.
Saudi leaders are also worried about Qatar's longtime links to Iran, the Shiite Muslim power vying for regional influence with Saudi Arabia, the leading Sunni Muslim power. Qatar is predominantly Sunni, with a Shiite minority.
In late May, Qatar's state-run news agency published comments from its emir, Sheik Tamim bin Hamad al Thani, expressing support for Iran, the militant groups Hamas and Hezbollah, as well as Israel, and suggesting President Trump would not stay in power. Qatari officials blamed the comments on hackers.
Turkey, which has good relations with Qatar and other Persian Gulf countries, has offered to mediate the diplomatic conflict. But the Muslim holy month of Ramadan is underway, to be followed by the Eid holiday. Many analysts don't expect a resolution until at least the beginning of July.
U.S. officials insisted that the rift would not affect the regional coalition fighting Islamic State.
"I am positive there will be no implications coming out of this dramatic situation at all, and I say that based on the commitment that each of these nations that you just referred to have made to this fight," Defense Secretary James N. Mattis told reporters Monday in Sydney, Australia.
The Pentagon said there was no immediate effect on operations at Al Udeid Air Base in Qatar, the U.S. military's largest such facility in the Middle East. The base, 20 miles southwest of Doha, is home to 10,000 troops as well as bomber jets, refueling planes, cargo aircraft and a high-tech center where U.S. commanders and allies orchestrate the daily air war against Islamic State militants.
"U.S. military aircraft continue to conduct missions in support of ongoing operations in Iraq, Syria and Afghanistan," Adam Stump, a Pentagon spokesman, said in a statement, adding, "We have no plans to change our posture in Qatar."
But the Pentagon is concerned about how the diplomatic break will affect the base in the long term, particularly if it becomes difficult for U.S. personnel to travel there, said U.S. defense officials, who declined to speak publicly.
The blockade comes just two weeks after Trump visited Saudi Arabia and urged members of the Gulf Cooperation Council, or GCC, a regional political and economic union, to join with him in an alliance against Iran.
Michael Knights, a Boston-based analyst at the Washington Institute for Near East Policy, said the message sent by U.S. officials at the Riyadh summit was clear: "Trump has subcontracted the fight against political Islam to them and they need to take the lead."
"This is them using that mandate to settle some old scores," Knights said. "There's always been this tension with Qatar, this rivalry between the UAE and Qatar, the Saudis and Qatar. What we're seeing now is a very brutal exercise in humiliation, to break Qatar's independent spirit."
U.S. Secretary of State Rex Tillerson downplayed the seriousness of the dispute and said the United States was willing to help resolve it.
"We certainly would encourage the parties to sit down together and address these differences…. We think it is important that the GCC remain unified," Tillerson said during a visit to Australia on Monday.
Iranian officials condemned the blockade as the latest instance of the U.S. expanding its influence in the region.
"What is happening is the preliminary result of the sword dance," tweeted Hamid Aboutalebi, deputy chief of staff of Iranian President Hassan Rouhani, referring to Trump's traditional dance with the Saudi king during last month's Riyadh summit.
Times staff writer W.J. Hennigan in Washington and special correspondent Ramin Mostaghim in Tehran contributed to this report.
6:35 p.m.: This article has been updated with analysis and U.S. reaction.
10:35 a.m.: This article was updated throughout with staff reporting.
4:55 a.m.: This article was updated throughout with impacts from the decision.
June 5, 1:10 a.m.: This article was updated throughout with additional details and background.