On the day Saudi Crown Prince Mohammed bin Salman jailed rival princes and gathered about his robes the trappings of power, a missile screamed toward the airport of Riyadh, the kingdom’s capital. It was shot down before it could reach the earth, but the Saudi government claimed to know every detail about where it came from.

“It was an Iranian missile, launched by Hizballah from territory occupied by the Houthis in Yemen,” Saudi Foreign Minister Adel al-Jubeir declared to CNN three days later, on Nov. 6, naming allies of Tehran. “Direct military aggression by the Iranian regime,” the Crown Prince added a day later.

So it goes between the two great Muslim powers of the Middle East, the Sunni kingdom and the Shi’ite republic, locked in a rivalry only rarely declared so nakedly. Most of the time, especially in recent years, Saudi Arabia and Iran fight through proxies. And Iran is winning most of them, on evidence less dramatic than a missile launch:

In Iraq, millions of Shi’ite pilgrims are now gathering in the cities of Najaf and Karbala for the annual Arba’een ritual. Millions are arriving from neighboring Iran, which has cemented a deep alliance with Iraq since the nominally secular but Sunni dictator Saddam Hussein was toppled by the U.S. in 2003. Today, the Shi’ite sense of brotherhood between the two nations is more robust than it has been for centuries — as is the cooperation between governments. The Popular Mobilization Forces called the Al-Hashd Al-Sha’abi, based on the Iranian Basij paramilitary force, outmatches the official Iraqi army in both manpower and morale.

In Syria, the government of Bashar Al-Assad would have collapsed years ago without the help of the Iranian-backed militant group Hizballah, Russian airpower solicited by Iran and Iranian soldiers euphemistically referred to as military advisors. The combined forces are slowly but steadily taking back land from both ISIS and other groups of rebels that the Saudis had backed.

In Yemen, where Saudi Arabia had hoped for a quick and decisive victory when it led an armed attack in 2015 in support of the country’s official President Mansour Al-Hadi, it has instead become bogged down in a costly war of attrition with the Zaidi Houthis, a Shi’ite sect that drew much closer to Iran after the Saudi attack.

Yet the reaction from the Islamic Republic to Saudi bellicosity has been uncharacteristically muted. While strongly denying any role in arming the Houthis, Tehran has limited itself to calling for peace and unity and blaming Mohammad bin Salman’s accusations on problems inside the kingdom.

“If you have internal problems in [Saudi] Arabia, try to solve those problems, why do you seek to make problems for others because of your own problems? Why do you speak against the countries of the region?” Iran’s president, Hassan Rouhani, said in a cabinet meeting on Wednesday according to Iran’s official news agency IRNA.

For Iran, an escalation of the proxy wars into a direct confrontation with Saudi Arabia would be counterproductive to say the least, especially since events on the ground are going their way, at least for the time being. Iran is not eager to test Saudi Arabia’s modern and state-of-the-art military hardware, purchased from the United States at a price tag of billions of dollars. And attacking the birthplace of Islam, with the two most holy sites of Islam, in Mecca and Medina, would be akin to propaganda suicide in the Islamic World, with the potential for uniting every Muslim in the world against them. It’s no accident that Saudi kings style themselves as “The Custodian of The Two Holy Mosques.”

Today, Iran has much more to lose than it did a decade and a half ago. Before the American wars following 9/11, the Islamic Republic had been boxed in by the Taliban’s Afghanistan to the east and Saddam Hussein’s Iraq to the west. At that time, international concern over its nuclear program was making Iran a pariah state, its only regional ally being Syria, and the sections of Lebanon where Hizballah held sway.

But now, especially after the 2015 nuclear deal it reached with global superpowers, the influence of the Islamic Republic runs high in many Middle Eastern capitals, and beyond. Tehran played host to Russian President Vladimir Putin and hopes to have French President Emmanuel Macron pay an official visit, in what would be a first since the 1979 Islamic Revolution. Barely a week goes by without the Islamic Republic’s most travelled foreign minister, Javad Zarif, either hosting foreign diplomats or visiting them around the world.

The Islamic Republic, finally within sight of its goal of becoming the region’s dominant power, considers a direct military confrontation with the House of Saud — which they believe to be on the verge of collapse — as far from desirable. Discretion, in their view, is the better part of valor.

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