WASHINGTON — President Trump thrust himself into a bitter Persian Gulf dispute on Tuesday, taking credit for Saudi Arabia’s move to isolate its smaller neighbor, Qatar, and rattling his national security staff by upending a critical American strategic relationship.
In a series of tweets, Mr. Trump said his call for an end to the financing of radical groups had prompted Saudi Arabia and four other countries to act this week against Qatar, a tiny, energy-rich emirate that is arguably America’s most important military outpost in the Middle East.
“During my recent trip to the Middle East I stated that there can no longer be funding of Radical Ideology,” he wrote in a midmorning post. “Leaders pointed to Qatar — look!”
Qatar has long been accused of funneling money to the Muslim Brotherhood — which has officially forsworn violence but is still accused of terrorism by some countries — as well as to radical groups in Syria, Libya and other Arab nations. But it is also home to two major American command posts, including a $60 million center from which the United States and its allies conduct their air war on Islamic State militants in Iraq and Syria.
Those contradictory roles may explain the mixed signals the administration sent after Saudi Arabia’s unexpected move. Secretary of State Rex W. Tillerson and Defense Secretary Jim Mattis initially tried on Monday to smooth over the rift, with Mr. Tillerson offering to play peacemaker and Mr. Mattis insisting it would have no effect on the campaign against the Islamic State.
Less than 12 hours later, however, Mr. Trump discarded that approach by putting his thumb on the scale firmly in Saudi Arabia’s favor. His tweets, which a senior White House official said were not a result of any policy deliberation, sowed confusion about America’s strategy and its intentions toward a key military partner.
“So good to see the Saudi Arabia visit with the King and 50 countries already paying off,” Mr. Trump wrote. “They said they would take a hard line on funding.” He added, “Perhaps this will be the beginning of the end to the horror of terrorism!”
Additionally, officials in Jordan said on Tuesday that the country would downgrade its diplomatic relations with Qatar and revoke the license of the Doha-based television channel Al Jazeera, Reuters reported.
On Tuesday evening, the president appeared to be trying to ease tensions. In a call with King Salman of Saudi Arabia, Mr. Trump said that unity among gulf nations was “critical to defeating terrorism and promoting regional stability,” according to a White House statement.
Administration officials said Mr. Trump was not trying to cause a rupture among Sunni Muslim nations in the Middle East. Rather, they said, he was expressing genuine frustration with Qatar’s record and making sure it followed through on the commitments it made in backing a new joint Terrorist Financing Targeting Center, which the president announced last month in Riyadh.
“The U.S. still wants to see this issue de-escalated and resolved immediately, keeping with the principles that the president laid out in terms of defeating terror financing,” said Sean Spicer, the White House press secretary.
Mr. Spicer denied that the president was taking sides. He said Mr. Trump had had a “very productive” discussion with Sheikh Tamim bin Hamad al-Thani, the 37-year-old emir of Qatar, during his visit to Riyadh. But another person briefed on the conversation said it had been noticeably colder than the president’s meetings with other gulf leaders.
In Washington, Qatar’s ambassador, Meshal bin Hamad al-Thani, expressed surprise at Mr. Trump’s tweets. “No one approached us directly and said, ‘Look, we have problems with this and this and this,’” he said in an interview with The Daily Beast.
There was little immediate threat to American military facilities in Qatar, administration officials and outside analysts said, not least because Qatar views America’s military presence as an insurance policy against the aggressive moves of its neighbors.
But the mood there was jittery. Government officials and news outlets described the cutoff of diplomatic relations, travel and trade as a “siege” and even as an attempt at a coup.
Those jitters have been intensified by suspicions that Russia was behind a cyberattack that published fake information on Qatar’s state news agency — a claim the United States is investigating, according to an official briefed on the inquiry, who spoke on the condition of anonymity. The official said it was unclear whether the hackers were state-sponsored.
An American diplomat warned that there was a temptation to blame malicious acts on the Russian government before the evidence had been weighed. But the same diplomat noted that Russia had much to gain from divisions among Iran’s rivals in the region, particularly if they made it more difficult for the United States to use Qatar as a major base.
“For sure, this is an attempt at regime change,” said Jamal Elshayyal, a senior producer for Al Jazeera, the Qatari-owned news channel that many in the region accuse of spreading extremist ideas.
Pentagon officials said they, too, were taken aback by Mr. Trump’s tweets, particularly given the American military’s deep ties to Qatar. The military has been eager to avoid political quarrels with the Qataris, a goal reflected in statements by its spokesmen.
“The United States and the coalition are grateful to the Qataris for their longstanding support of our presence and their enduring commitment to regional security,” Lt. Col. Damien Pickart, spokesman for the Air Force component of the Central Command, said on Monday.
Al Udeid Air Base, outside the Qatari capital, Doha, is home to more than 11,000 American and coalition service members. Mr. Mattis made a point of visiting in April, spending three nights in Doha, where he met with the emir.
Mr. Trump’s tweets also appeared to contradict the American ambassador to Qatar, Dana Shell Smith, who this week retweeted a post of hers saying Qatar had made “real progress” in curbing financial support for terrorists.
On Tuesday, an American diplomat in Doha said that Qatar’s relationship with the United States was “strong” and that it had made strides: prosecuting people suspected of funding terrorist groups, freezing assets and putting stringent controls on its banks.
Not for the first time, Mr. Trump’s comments differed sharply from those of his top national security aides.
“We certainly would encourage the parties to sit down together and address these differences,” Mr. Tillerson told reporters in Sydney, Australia, where he and Mr. Mattis were meeting with officials on Monday.
Mr. Mattis added, “I am positive there will be no implications coming out of this dramatic situation at all.”
In addition to hosting the air command center, Qatar is the home of the forward headquarters of the United States Central Command and an American intelligence hub in the Middle East.
It also has deep ties to American academia, providing funding and property to build Middle Eastern campuses for six major universities, including Cornell, Georgetown and Northwestern.
Qatar’s financing of radical groups has long been a source of tension with Washington. But the United States has generally avoided taking sides in the regional feuds in the Persian Gulf, because it has strategic partnerships with several countries and most of them, including Saudi Arabia, have a record of financing extremist groups.
“Clearly, the Saudis and the Emiratis felt they had someone in the White House who would take their side,” said Robert Malley, who coordinated Middle East policy in the Obama administration. “This puts Qatar in a tough position: Either make a dramatic policy shift or face deeper isolation.”
Others analysts were more critical, saying the Saudis had exploited Mr. Trump by seizing on the good will generated during his visit to carry out a long-planned move against a smaller neighbor.
“The Saudis played Donald Trump like a fiddle,” said Bruce O. Riedel, a former intelligence analyst who advised Mr. Obama and now works at the Brookings Institution. “He unwittingly encouraged their worst instincts toward their neighbors.”
It is not the first time the White House has struggled to explain Mr. Trump’s statements about a security partnership. Just last month, during a visit to NATO headquarters in Belgium, he declined to reaffirm America’s commitment to the alliance’s principle of mutual defense, after a senior administration official had told The New York Times he would.
That line was deleted from Mr. Trump’s speech shortly before he delivered it, according to Politico, to the surprise of officials including Mr. Tillerson and Mr. Mattis.
On Tuesday, Mr. Spicer described persistent questions about the episode as “a bit silly,” saying Mr. Trump’s mere presence at the NATO ceremony was evidence of the American commitment to mutual defense.
Reporting was contributed by David D. Kirkpatrick from Doha, Qatar; Michael R. Gordon, Helene Cooper and David E. Sanger from Washington; Patrick Kingsley from Istanbul; and Sheera Frenkel from San Francisco.