Why the sudden split in Middle East relationships? Look to Iran and Sunni vs. Shia

The move by several Arab states to sever diplomatic ties with Qatar on Monday seemed to catch the world by surprise, but it had been in the works for some time, as Saudi Arabia and Egypt, among others, had grown fed up with the meddling of the tiny Gulf state.

Accusing the Qatari government of supporting militant groups such as the Muslim Brotherhood, the nations which include Bahrain, the United Arab Emirates and Yemen were emboldened by Donald Trump's call during his visit to the region two weeks ago to "drive out the extremists."

Trump waded into the deepening rift again today, siding with Saudi Arabia and the others in a series of tweets that appeared to endorse the accusation that Qatar funds terrorist groups.

Qatar vehemently denies the accusations.

The U.S. president also suggested that the decision to sever ties was inspired by an anti-Islamist speech he made in Riyadh last month, writing on Twitter that his recent Mideast trip was "already paying off."

The dispute is the most serious to hit the region since the formation of the Gulf Co-operation Council 36 years ago.

Saudi Arabia said it acted as a result of Qatar's "embrace of various terrorist and sectarian groups aimed at destabilizing the region," including ISIS and al-Qaeda.

This crisis also has a lot to do with Iran.

Qatar has, publicly at least, tried to avoid taking sides in the simmering regional spat between Sunni powerhouse Saudi Arabia and Shia-led Iran, but the dispute boiled over when the kingdom on Monday accused the Qatari government of backing "Iranian-backed terrorist groups."

The Sunni states were enraged by recent comments made by Qatar's ruler Sheikh Tamimbin Hamad al-Thani, in which he allegedly said "there is no wisdom in harbouring hostility toward Iran."

When news of the emir's comments was broadcast around the Arab world, Qatar's official news agency said it had been hacked by "an unknown entity," adding that a "false statement attributed to His Highness" had been published.

For several Middle Eastern countries though, the damage was done.

Qatar has been accused of stirring sentiment that brought about the Arab Spring revolutions of 2011, which led to the overthrow of the regimes in Tunisia, Libya and Egypt.

While the country is small, it's had an outsized influence in the Middle East, largely due to its backing of the Al-Jazeera news network, which is based in Doha. Al-Jazeera's broadcasts, which routinely criticize Saudi Arabia and other regional governments, have long drawn the ire of Middle Eastern kings, emirs and presidents.

Egypt's exasperation

Egypt has accused the Qataris of backing the Muslim Brotherhood, the oldest Islamic movement in the world. Its candidate Mohammed Morsi won the country's first democratic elections in 2012, but was overthrown by the military a year later.

Morsi's successor, president Abdel Fattah el-Sisi, a former chief-of-staff of the country's armed forces, ordered a crackdown against the brotherhood. That brought a significant chill in relations with Qatar, which had been a close ally before the Arab Spring.

Canadian journalist Mohammed Fahmy was ensnared in a wave of anti-Al-Jazeera sentiment in Egypt in 2013, jailed for more than 400 days as an alleged supporter of the Muslim Brotherhood. He was pardoned and released in 2015.

Qatar's immediate response to Monday's moves from the Arab states was to deny the accusation that it supports militant groups as "unjustified," saying it was "based on claims and allegations that have no basis in fact."

But as pressure on the Gulf state mounted Tuesday, Qatar's foreign minister signalled that Doha was ready for mediation to try to resolve the crisis.

Trump's tweets were seemingly at odds with comments made by U.S. officials just one day earlier, when Secretary of State Rex Tillerson said without taking sides that he's prepared to play a role in calming tensions.

"We certainly would encourage the parties to sit down together and address these differences," Tillerson said Monday.

The U.S. has a lot at stake in this dispute. Qatar is home to the sprawling al-Udeid Air Base, which houses more than 10,000 American military personnel who carry out operations in the Middle East and Afghanistan.

The base is key to the U.S.-led fight against ISIS in Iraq and Syria, and some analysts think this diplomatic dispute could have an impact on the mission, as it would force some nations that contribute warplanes, such as Bahrain, to withdraw their military liaison officers from the Qatari base.

The U.S. military stuck to a message of reassurance Tuesday and offered its backing for Qatar, praising its "enduring commitment to regional security," while downplaying the effect of the crisis on the anti-ISIS mission.

"We've seen no impact to our operations and all flights continue as planned," said Lieutenant Colonel Damien Pickart, a spokesman at U.S. Air Forces Central Command.

U.S. realignment?

Trump's visit to Saudi Arabia last month may have played a role in the Arab state's decision to split with Doha.

In an effort to calm regional fears that, under Barack Obama, the United States had abandoned the Middle East, Trump lavished praise on his Saudi hosts, saying "we begin a new chapter that will bring lasting benefits to our citizens."

The takeaway from the trip was that Washington was now more in line with Saudi Arabia and the United Arab Emirates, while the president seemed to put some distance in the relationship with Qatar.

Several former top U.S. Middle East officials had warned that, despite the close military relationship between the U.S. and Qatar, Doha wasn't much of a friend.

"Allies at a minimum share our interests, support our basic policies, and see common enemies," Dennis Ross, a former senior Middle East adviser to Barack Obama, wrote in USA Today.

"They don't give support, especially material support, to those who threaten our interests and the interests and well-being of our friends and partners.

"By this measure, Qatar is most definitely not an ally."