Saudi Arabia's reliance on a personal, transactional relationship with Donald Trump is being tested as Houthi attacks on the kingdom escalate and Washington declines requests from Crown Prince Mohammed bin Salman for military assistance. The refusal has exposed a central vulnerability in Riyadh's foreign policy: years of cultivating the US president through arms purchases and investment pledges have not translated into guaranteed protection.
For years, Prince Mohammed built close ties with Trump and his son-in-law and former senior adviser Jared Kushner, reading the president's approach to power as fundamentally transactional. Saudi Arabia signed deals to buy billions of dollars' worth of American weapons and invested billions more in US companies. Days after Trump returned to the White House in January 2025, the crown prince pledged to expand investment and trade with the United States by $600bn over four years. He later said the figure would rise to nearly $1tn, though it was never entirely clear how the kingdom could channel a sum close to its entire annual GDP into a foreign economy within a few years.
Those commitments were widely presented as evidence of a durable strategic partnership. In practice, they appear to have bought Riyadh influence in Washington without securing the kind of security guarantee the crown prince now needs. When Houthi attacks intensified and Prince Mohammed called for American help, the US turned down the requests, according to the account of the relationship. The episode suggests that the Saudi leadership misjudged what its money could secure.
The Houthis, based in Yemen, have escalated their attacks on Saudi Arabia, raising pressure on Riyadh at a moment when its main external patron appears unwilling to intervene. For the kingdom, the threat is not only military but political: the crown prince has staked much of his standing on the claim that his ties to Washington deliver tangible security benefits. A US refusal undermines that narrative at home and abroad.
The relationship between Trump and Prince Mohammed has long been unusually personal. Kushner, who served as a top adviser in the first Trump administration, was a central channel to Riyadh, and the crown prince worked to maintain access to the president's inner circle. Saudi investment in American companies and large-scale weapons purchases were part of a broader effort to keep the relationship warm. The $600bn pledge, announced shortly after Trump's return to office, was the most visible expression of that strategy.
Yet the arrangement was always asymmetrical. Riyadh needs American security backing; Washington values Saudi money and arms contracts but has its own priorities. Trump's transactional style means commitments are weighed case by case, and Saudi requests for help against the Houthis have apparently not cleared that bar. The result is a gap between what Riyadh believes it has purchased and what Washington is prepared to deliver.
The crown prince's decision to promise investment approaching $1tn raised eyebrows even among observers sympathetic to the kingdom, given the scale relative to Saudi Arabia's economy. Such pledges are difficult to verify and depend on oil prices, capital flows and political conditions. They also create expectations in Washington that Riyadh may struggle to meet, while giving the US president leverage in future negotiations.
For Saudi Arabia, the lesson is that close ties to a single American leader are not a substitute for a formal security relationship. The kingdom has long sought stronger US commitments, but successive administrations have been cautious about binding guarantees. Trump's willingness to accept Saudi money has not changed that fundamental caution, and the Houthi escalation has made the distinction painfully clear.
The episode also carries implications beyond Riyadh. Gulf states watching the relationship may reconsider how much they can rely on personal diplomacy with Washington. If the US can decline a Saudi request for help despite billions in arms deals and investment pledges, other partners will recalibrate their expectations. For Prince Mohammed, the challenge now is to manage a security threat while explaining why his expensive courtship of Trump has not produced the protection he sought.