On Monday, the governments of Saudi Arabia, the United Arab Emirates, and Bahrain announced that they have severed diplomatic relations with Qatar.
Caught in the diplomatic crisis is the country's national airlines, Qatar Airways.
All three Gulf nations have refused the Qatari airline access to its airspace. Unfortunately for the Doha, Qatar-based airlines, Saudi Arabia along with the Emirates of Abu Dhabi and Dubai happen to be some of its biggest markets.
In fact, according to CAPA – The Center for Aviation analyst Will Horton, Saudi Arabia is Qatar Airways' largest market. Conversely, the Qatar Airways' presence in Saudi Arabia is the largest of any international airline.
Qatar Airways was not immediately available for comment.
The three Persian Gulf governments accuse Qatar of destabilizing the region's security through its support of the Islamic Brotherhood, ISIS, and Iran.
In a statement, the UAE's Ministry's Foreign of Affairs & International Cooperation wrote:
"Closure of UAE airspace and seaports for all Qataris in 24 hours and banning all Qatari means of transportation, coming to or leaving the UAE, from crossing, entering or leaving the UAE territories, and taking all legal measures in collaboration with friendly countries and international companies with regards to Qataris using the UAE airspace and territorial waters, from and to Qatar, for national security considerations."
While the countries are free to refuse landing rights, it is unclear if Bahrain and the UAE can legally ban Qatar Airways from its airspace. As signatories to the International Air Services Transport Agreement , Bahrain the UAE can't legally shut off its airspace to fellow signatory Qatar.
Saudi Arabia is not an IASTA member country and can legally shut Qatar Airways out of its airspace.
Over the past two decades, Qatar Airways has grown to become one of the most influential international airlines in the world. In 2015, consumer aviation website Skytrax named Qatar Airways the best airline in the world .