With Washington and Tehran nearing the brink of war, the rest of the world looks on nervously. But which U.S. allies would actively back the United States should a full-scale war break out?

More supportive would most likely be some of the Gulf monarchies such as Saudi Arabia and Bahrain. Many of these countries house U.S. bases and share the Trump Administration’s hostility to Iran. Several of them supported the U.S.’s withdrawal from the Iran nuclear deal, and Saudi Arabia is already engaged in fighting Iranian-backed Houthi fighters in Yemen. Though the Gulf monarchies possess significant levels of military hardware, they would most likely primarily serve as a launchpad for U.S. attacks on Iran rather than as active participants.

However, the Gulf is by no means unanimous on this point. A notable exception is Oman, which is generally the most peaceful country on the Arabian Peninsula. Located across from Iran along the Straits of Hormuz, the sultanate served as a backchannel between the U.S. and Iran in the leadup to open and direct talks between the two. Additionally, Oman has been pushing for years for Iranian oil imports as well as an underwater gas pipeline connecting the two countries.

A more recent change in the Gulf has been Qatar. Though initially part of the anti-Iran axis, the oil-rich state has been the target of a multi-year campaign led by Saudi Arabia and others to isolate it diplomatically and economically. Alleged plans by some of the Gulf Cooperation Council countries to invade Qatar, which houses 10,000 U.S. servicemen at the Al Udeid Air Base, might explain why Qatar’s foreign minister traveled to meet his Iranian counterpart a day after the assassination of Qassem Soleimani.