Crown Prince Mohammed bin Salman arrives Monday in Washington, D.C., bringing the brash foreign policy that has shaped Saudi Arabia’s more muscular stance in the Middle East to counter archenemy Iran.

The Trump administration and lawmakers now need to weigh whether to support the prince’s more confrontational approach with Iran and risk sparking a regional conflict, or seek to moderate his diplomacy.

“The key question,” says Brian Katulis, a fellow at the Center for American Progress, a Washington think tank, “is how does America best shape Saudi Arabia and influence how it engages?”

For years, the U.S. could count on the kingdom to anchor its agenda in the Middle East. In exchange for U.S. military protection, Saudi Arabia guaranteed a steady supply of oil and provided a bastion of stability in a volatile region.

Prince Mohammed upended that status quo after his father, King Salman, assumed the throne three years ago. At home, the father-and-son duo have sought to transform the kingdom’s economy, ending its reliance on oil. And abroad, Saudi Arabia has abandoned the kingdom’s traditionally passive foreign policy in favor of trying to roll back Iran’s pervasive influence—an approach that has dragged it into a devastating war next door in Yemen.