Saudi Arabia more than doubled its already hefty lobbying budget last year to help navigate a trifecta of challenges to its relationship with the United States.

The conservative Gulf kingdom added five new firms to its roster in 2015, lobbying records show, and shelled out more than $9.5 million to influence US policymakers — up from $4.1 million the year before. The spending spree came amid renewed scrutiny of Riyadh’s role in the Sept. 11, 2001, terror attacks, rising US concerns over its increasingly assertive posture in the region and lingering Saudi misgivings over President Barack Obama’s overtures to regional rival Iran.

Saudi largesse has continued apace in 2016, with the Foreign Ministry hiring international law firm DLA Piper in May to “strengthen […] the ability of the United States and Saudi Arabia to advance mutual national security interest.” And an arm of the Saudi Royal Court retained Republican bigwig Haley Barbour’s lobbying and PR firm BGR that same month to communicate “priority issues … to relevant US audiences.”

The lobbying boost appears to have helped put the bilateral relationship back on an even keel, at least temporarily, after a stormy stretch sparked by Obama’s stated desire to reassess Washington’s support for its traditional allies in the region. While much ink has been spilled over the president’s disparaging description of Gulf states as “free-loaders” in an interview with The Atlantic earlier this year, the administration has also praised Saudi Arabia’s announced creation of a coalition of 34 Muslim nations to defeat terrorism threats late last year.