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.

A United States Air Force pararescue airman attached to the 10th Special Forces Group (Airborne) and a Qatar Joint Special Forces soldier discuss the way ahead during an Invincible Sentry 2019 training scenario near Zekreet, Qatar, on March 24, 2019. U.S. Central Command used IS19 to evaluate the capabilities of its subordinate units to mitigate crises within the region. (U.S. Army photo by Staff Sgt. Brandon McIntosh)

Perhaps the most anti-Iranian leader in the world is Israel’s Benjamin Netanyahu, who for decades has led the pro-war camp as well as having sought to bring his country closer to some of the Gulf states. While Israel has attacked Iranian forces in Syria and possesses the capability to strike Hezbollah in Lebanon, anti-Israel sentiments throughout the region and the relatively small size of its military, is likely to preclude any significant Israeli participation in a ground offensive. If anything, its entry may unite the different segments of Iran’s population. It was for this reason that the George H.W. Bush Administration called for Israel not to retaliate against Iraqi Scud missile attacks during the Persian Gulf War.

In general, these countries have achieved tactical successes, but strategic failures in recent wars. Israel’s war in Lebanon in 2006 resulted in significant devastation and an unbalanced death toll, yet Israel was unable to inflict any long term injuries on Hassan Nasrallah’s forces. Likewise, the Saudi-led war in Yemen is approaching its fifth year with little to show for it.

The U.S. should not expect to receive any support — even symbolic — from Iraq. Unannounced airstrikes, as well as the unpermitted deployment of U.S. troops from Syria, has left the United States with virtually no friends in Baghdad whether Sunni or Shi’ite.

It is doubtful that Turkey would support the U.S. in a war against its neighbor. Ankara will not want to receive any more refugees from a country with a population four and a half times greater than that of Syria, which itself has already produced roughly four million refugees. In addition to not wanting a third Middle Eastern war-torn country along its border, a collapsed Iranian state will likely prove to be a fertile breeding ground for yet another active Kurdish movement. Should that be the case, the U.S. and Turkey could easily end up on the opposite side of a civil war.