Secretary of State John Kerry recently traveled to Riyadh to reassure the Kingdom of Saudi Arabia and other Gulf states that the U.S. stood with them. “Nothing has changed” as a result of the nuclear pact with Iran, he insisted.

Washington’s long relationship with Riyadh was built on oil. There never was any nonsense about sharing values with the KSA, which operates as a slightly more civilized variant of the Islamic State. The royals run a totalitarian system which prohibits political dissent, free speech, religious liberty, and social autonomy.

At a time of heavy U.S. dependence on foreign oil a little compromise in America’s principles might have seemed necessary. Today it’s hard to make a case that petroleum warrants Washington’s “special relationship” with Saudi Arabia. The global energy market is expanding; the U.S. will soon become a petroleum exporter. The royal regime cannot survive without oil money and has continued to pump even as prices have collapsed.

In recent years Washington also treated Riyadh as an integral component of a containment system against Iran. Of course, much of the “Tehran problem” was made in America: overthrowing Iranian democracy ultimately led to creation of an Islamist state.

Fears multiplied as Tehran confronted its Sunni neighbors along with Israel and continued the Shah’s nuclear program. Overwrought nightmares of Islamic revolution throughout the region encouraged America’s fulsome embrace of the KSA and allied regimes.

But this argument for supporting the Saudi royals has become quite threadbare. Saudi Arabia is well able to defend itself. In 2014 it came in at world number four with $81 billion in military expenditures, a multiple of Iran’s total.

Threats of subversion reflect internal weaknesses beyond Washington’s reach: the kingdom’s general repression and particular mistreatment of its Shia minority, including the recent execution of cleric Nimr al-Nimr, who urged nonviolent opposition to the monarchy.

Moreover, the nuclear agreement creates a real opportunity for change in Iran. The process will not be quick or easy. However, in contrast to the KSA, there are (carefully circumscribed but real nonetheless) elections, political debate, religious diversity, generational resistance, and liberal sentiments.

Whatever the alleged benefits of the Saudi alliance, America pays a high price. First is the cost of providing free bodyguards for the royals.

For this reason the U.S. initiated the first Gulf War and left a garrison on Saudi soil. At the Saudis’ behest Washington backs their misbegotten war in Yemen and remains formally committed to the overthrow of Syrian President Bashir al-Assad, the strongest force opposing the far more dangerous Islamic State.

Saudi Arabia also tramples American values beyond its own borders. In next-door Bahrain Riyadh help suppress the majority Shia population. The KSA also has underwritten extremist Islamic teaching in madrassahs around the world.

Moreover, Saudi money backed al-Qaeda and people performed 9/11. Similar private support for extremist violence apparently continues.

Over the last few years Riyadh’s behavior has become more harmful to America’s interests. The monarchy has been pushing to oust Syria’s Assad without worrying about who or what would follow. Moreover, in Yemen Saudi Arabia turned a long-term insurgency into another sectarian conflict.

By executing Sheikh al-Nimr the KSA triggered sectarian protests in Bahrain, Iran, Iraq, and Lebanon. Riyadh responded by breaking diplomatic relations with Iran, undermining political negotiations to resolve Syria’s civil war.

Of course, the fact that Riyadh is a destabilizing force does not mean that the U.S. should attempt regime change in Riyadh. But Washington should stop lavishing support on the Saudi royals. Particularly important, the U.S. should disentangle itself from the KSA’s misbegotten war in Yemen.

As I point out in National Interest: “The two countries need a new, more normal relationship. They should work together when advantageous and disagree when appropriate. Sell weapons to Riyadh without committing to provide a royal bodyguard.”

Most important, Washington should continue to forge a better relationship with Tehran. Balance should return to American policy in the Middle East.