Qatar crisis: What does it mean for US military in the Gulf?

The decision by Saudi Arabia, Egypt and the UAE to break off diplomatic ties with Qatar is likely to cause some headaches in the US as the countries are major military allies and host important US bases.

US Secretary of State Rex Tillerson was quick to downplay suggestions that the spat could undermine the fight against the Islamic State group in Iraq and Syria.

I am confident there will be no implications coming out of this diplomatic situation at all

- James Mattis, US defence secretary

"I do not expect that this will have any significant impact, if any impact at all, on the unified - the unified - fight against terrorism in the region or globally," Tillerson told reporters in Sydney after meetings between Australian and US foreign and defence ministers.

“I think what we’re witnessing is a growing list of irritants in the region that have been there for some time, and obviously they have now bubbled up to the level that countries decided they needed to take action in an effort to have those differences addressed,” he added.

“We certainly would encourage the parties to sit down together and address these differences,” he added.

Defence Secretary James Mattis, who accompanied Tillerson, also sought to dismiss concerns. “I am confident there will be no implications coming out of this diplomatic situation at all,” he said.

Qatar is home to the Al-Udeid Airbase, from where the United States carries out air strikes against militants in the region. Located 20km southwest of the capital Doha, the base hosts more than 11,000 American troops and has been used since 2016 to bomb Islamic State in Iraq and Syria. US Air Force Central Command (also known as Centcom), Combined Air and Space Operations Center and the 379th Air Expedition Wing are all housed at the base.

Bahrain houses the US Navy's Fifth fleet, which patrols the seas of the Middle East and Central Asia.

Saudi Arabia hosts five air bases. A $110bn arms deal made between the US and Saudi during President Donald Trump's recent trip has further cemented the military relationship between the two countries.

US faces difficult questions

The crisis is likely to leave Washington asking some difficult questions about its future military presence in the region. Jean-Marc Rickli, head of global risk and resilience at the Geneva Centre for Security Policy, told Reuters: "You have a shift in the balance of power in the Gulf now because of the new presidency: Trump is strongly opposed to political Islam and Iran."

"He is totally aligned with Abu Dhabi and Riyadh, who also want no compromise with either Iran or the political Islam promoted by the Muslim Brotherhood."

Some have even suggested that the US may pull out of Al-Udeid.

Dennis Ross is a former US diplomat, who served under former presidents George HW Bush, Bill Clinton and Barack Obama.

“I wouldn’t be surprised at all if there’s some discussion internally in the Trump administration to make it clear to Qatar that if need be, we’re prepared even to move (from) the base,” he told Sky News Arabia.

“When I was in the Obama administration… I wanted us to make it clear that just because we have a big base there doesn’t mean… we’re going to turn a blind eye to what they (Qatar) are doing."