In January, the Pentagon transferred 10 low-level Guantanamo Bay detainees to Oman, marking the largest resettlement of such prisoners in a single day since the US military began detaining suspected terrorists there 14 years ago. Oman has become the primary destination for transferred prisoners, having accepted roughly half of the Guantanamo inmates released since January 2015.

The US military had resettled six Yemeni prisoners in Oman last June, and soon after, the Pentagon expressed its gratitude for Muscat’s “willingness to support ongoing US efforts to close the Guantanamo Bay detention facility” and for its “appropriate security and humane treatment measures.” The prisoner transfers underscore the relationship between Muscat and Washington.

As a stable Arab state that has maintained a military partnership with the United States since 1980, Oman plays a relatively low-profile, but influential role in Washington’s Middle East policy. Maintaining neutral stances on Middle Eastern conflicts while keeping diplomatic ties open to all sides, Muscat has served on several occasions as a diplomatic back channel for the United States. US Secretary of State John Kerry has said of Oman that it offers "wise advice and [helps] find solutions to various problems in the region.” The Iranian nuclear agreement is one important example of this.

Iran’s nuclear program was a hot-button issue during President Barack Obama’s bid for re-election in 2012. At the time, Sultan Qaboos bin Said had assured Obama that Oman could serve as a back channel to the Iranians. That summer in Muscat, US officials and their Iranian counterparts held their first secret meeting, marking the beginning of the negotiations that ultimately led to last year’s watershed nuclear deal between the six world powers and Iran.