But barely had Trump departed when dramatic rifts again became evident.
As early as Tuesday - two days after the summit - Qatar's government felt obliged to make an official declaration in front of the press about a video that had been made accessible to the public. The video showed alleged quotations in writing that were attributed to the country's emir, Sheikh Tamim bin Hamad Al Thani (top photo), and caused a considerable stir in other Gulf states. That was because in it, the emir had seemingly found words of praise for the Muslim Brotherhood and the militant groups Hezbollah and Hamas.
"No one has the right to accuse us of terrorism - just because they declare the Muslim Brotherhood a terrorist group or because they are not ready to tolerate the kind of resistance embraced by Hamas or Hezbollah," the emir was quoted in the video. He also appears to have said: "The real danger lies in the behavior of certain governments which have bred terrorism themselves - by adopting an extreme version of Islam which does not correspond to the truth (of Islam)."
Hacked or not hacked?
It was immediately clear in the Arab world that those words were directed at Saudi Arabia. In this respect, the spat was apt to rekindle the old rivalry between Qatar and Saudi Arabia. Apparently, it was also for this reason that Qatar's government quickly backpedaled with an official statement maintaining that the server of Qatar's state news agency had been hacked, and that the video was a fake. The alleged statements by the emir had been smuggled onto the server; they had, in fact, never been made, according to the declaration. Qatar would make an effort to track down those responsible, it said.
Whether the video was a fake or not, the issue has since been hotly debated, sparking a veritable media war in the Gulf. One thing is certain: The video is a reflection of fundamental frictions between Saudi Arabia and Qatar which have been smoldering for many years and which relate to two issues in particular - the close relationship between Qatar and the Muslim Brothers, and the role played by the emirate during and after the uprisings in the Arab world in 2011.
Rivalry between Qatar and Saudi Arabia
Qatar had supported the "Arab Spring" in particular through its broadcaster Al-Jazeera. Qatar's leaders viewed the uprising as an opportunity for the small emirate to increase its political options in the region. To this end, it also supported secular movements that, either directly or indirectly, called the legitimacy of theocratic regimes into question - in particular, that of Saudi Arabia. The statements attributed to the emir were very much in accordance with Qatar's policies up to now, Egyptian media researcher Hafez al-Mirazi told DW.
The relationship between Qatar and Saudi Arabia is also strained because of the two states' different approaches to interaction with the Muslim Brotherhood. Whereas Qatar has, for a long time, considered cooperation with the Islamists as a way to gain influence in the Sunni world, Saudi Arabia repudiates them: After the kingdom took in numerous Muslim Brothers in the 1970s only to see them setting up an opposition movement against the state's leadership, it has seen them as a threat to regional, and thus its own, stability. In Yemen, however, the Saudis don't appear to have qualms about the Muslim Brothers' influence.
Harsh rhetoric from the US
Qatar's political rivals feel encouraged by the similar criticisms emanating from the US. Erem News, which is based in the United Arab Emirates, recently reported on an appearance of former US Defense Minister Robert Gates at a conference in Washington on the topic "Qatar and the Muslim Brotherhood." At it, Gates accused Qatar of having welcomed the Brothers with open arms for too long.
Gates also maintained that Qatar, which has a little more than 2.6 million citizens, was aiming for political clout that was manifestly inconsistent with its size. At the same time, the "Foreign Policy" website published an article written by John Hannah, a former adviser to Dick Cheney when he was vice president, in which Qatar was described as an unreliable partner of the US.
A new situation after Trump's visit
The fact that the old dispute between Qatar and some of its neighbors is seeing a new and sudden escalation could have something to do with Trump's visit to Riyadh, according to political scientist Kristian Coates Ulrichsen of Chatham House, a British think tank.
"It may be the case that the Saudis and Emiratis feel emboldened by the success of their reset of ties with the Trump presidency to become more assertive in regional affairs," he told AFP news agency.
But it's not only those two states that are getting tough with Qatar in the wake of the Riyadh summit - Egypt has followed their example. The broadcaster Al-Jazeera, blocked in Saudi Arabia since the beginning of the week, has now also been blocked by Egypt. For that country's regime, it's a golden opportunity: For a long time it has been complaining about Al-Jazeera's reporting, and it views the Muslim Brotherhood as public enemy number one.