RIYADH, Saudi Arabia — The United States is negotiating cost-sharing terms with Saudi Arabia for an expanding military mission aimed at ensuring the kingdom is protected from attacks on critical oil infrastructure, officials said.
Milley, in his first visit to this key U.S. ally since becoming President Trump’s chief military adviser this fall, met with Crown Prince Mohammed bin Salman and other leaders during his visit.
Trump authorized a boost to the relatively light U.S. footprint in Saudi Arabia, from an advisory mission that stood around 800 to a force of about 3,000, following the Sept. 14 assault on Saudi oil facilities, which Saudi and U.S. officials said was launched by Iran in an major escalation of regional tensions.
The troops will operate additional assets designed to help the Saudi military guard against Iranian attacks, including four Patriot batteries, a terminal high altitude area defense system, or THAAD air defense system, and two squadrons of fighter jets. Financial responsibility for the deployment has taken on unusual visibility after Trump, who has criticized allies for not contributing enough to shared defense, promised the oil-rich kingdom would pay “100 percent of the cost.”
The officials, who spoke on the condition of anonymity, said the two countries are negotiating “burden-sharing” arrangements but the kingdom is expected to provide financial support for some elements of the expanded U.S. military presence, including upgrades to a major air base, fuel, water and logistics.
Military officials say the deployment has a dual purpose: to fill in gaps in the Saudi Arabia’s air defense network, which in recent years has been oriented southward toward threats from Houthi rebels in Yemen rather than east or north toward Iran, and to prevent any potential Iranian action by raising the stakes.
Speaking to reporters traveling with him on a tour of Middle Eastern nations, Milley said it was important for potential adversaries to have a clear understanding that the United States was willing to employ force if required.
“So we want to maintain significant military capability within the region to reassure allies and deter Iran from aggression,” he said. “As long as Iran knows we’ll use it, I think it’ll be effective.”
The U.S. troops sent to Saudi Arabia make up a relatively small part of an overall regional presence that exceeds 60,000, but officials say the new deployments reflect a worrying uptick in Iranian attacks
The incidents also include mine attacks on Arab and European vessels. In June, Trump authorized but called off a strike on Iranian targets after Iran shot down an American drone that it said had veered into its airspace.
Iran denied involvement in the September attack, for which Yemeni Houthi rebels linked to Tehran initially asserted responsibility.
Military officials say one important aspect of the deployment is the presence of American forces in more locations across the kingdom. They believe Iran has demonstrated its reluctance to target American personnel, either directly or indirectly, in part because Trump has made clear that would trigger a military response.
“When you internationalize . . . it makes it harder for the Iranians to lash out because they’re now not just lashing out at a [Gulf] country,” said a senior defense official who spoke on the condition of anonymity because he was not authorized to speak on the record.
The Iranian reluctance is a change from the years following the 2003 U.S. invasion of Iraq, when U.S. officials estimate Iranian backed militias killed at least 500 American troops.
Now, American forces say, Iran seeks to strike back against sanctions imposed by the Trump administration, which have taken a severe toll on its economy and jeopardized its ability to finance armed proxies in the region.
The deployment is also a reflection of Saudi military capability, which U.S. military officials have long said was lacking.
Milley met with Saudi leaders on Monday and Tuesday as part of a regional tour that also included stops in Israel, Jordan, Bahrain, Kuwait and Iraq.
Kenneth Pollack, a former White House and CIA official who recently wrote a book about militaries in Arab countries, said Saudi Arabia continues to struggle in numerous areas such as mounting large-scale operations. The kingdom has been criticized for its role in the war in Yemen, where Saudi planes have repeatedly struck civilian targets.
But Pollack said the Sept. 14 attack on Saudi oil facilities, which involved a barrage of drones and missiles, would have been difficult even for the United States to repel.
“If terrorists or Iranians were down in Mexico or Canada and were mounting this kind of strike against us, we’d have a really hard time,” Pollack said.
Pentagon officials are seeking to respond to a perceived threat from Iran at a time when they are also hoping to reorient toward east Asia and the rapid military gains made by China. The Saudi deployment and other steps to reinforce the posture in the Middle East are examples of why, despite a recent overhaul to the national military strategy, it will be a challenge to do so.
In a parallel attempt to build international support for deterring attacks like the recent ones blamed on Iran, the United States is leading a clutch of partner countries in a new maritime initiative based in Bahrain that aims to increase surveillance across Middle Eastern waters that are central to global commerce.