Iranian Supreme Leader Ayatollah Khamenei launched his latest rhetorical broadside at Iran’s arch-rivals in Saudi Arabia from a ceremony commemorating the Muslim holiday of Ramadan on Saturday. Khamenei said the Saudi rulers are “worthless, inept, and villainous.”

Khamenei also insulted the Saudis as “idiots” for thinking they could purchase the friendship of “pagans and enemies” with their oil money, describing them as “milk cows for the Americans.”

Khamenei said the Muslim world is in “grave danger” because of leaders like the Saudis and their “refusal to follow the Koran and lack of belief in the truth.” The Saudi monarchy is a major force in the world of Sunni Islam, while Iran’s theocracy leads the Shiites, putting them on the opposite side of a religious schism that reaches back to the 7th Century.

That ancient conflict is mixed with contemporary geopolitical concerns, such as the civil war in Yemen, which has become a proxy war between Iran and Saudi Arabia.

The Supreme Leader of Iran, which supports the Shiite Houthi insurgents against the internationally recognized government of Yemen, blamed the Saudis for the continuing bloodshed in that war-torn country, as well as the oppression of Shiites by the Sunni government of Saudi Arabia’s allies in Bahrain. Iran’s Foreign Minister recently added another link to that chain of blame by accusing U.S. President Donald Trump of emboldening the government of Bahrain to crack down on Shiite demonstrators.

“They act cordially towards the enemies of Islam while having the opposite behavior towards the Muslim people of Bahrain and Yemen. They will face certain downfall,” Khamenei predicted.

He blasted the Saudis for signing a multibillion-dollar arms deal with the “infidel” Americans, saying that the money should have been used to “improve the lives of their own people.”

Fox News notes that recently re-elected Iranian President Hassan Rouhani, whose more moderate approach is frequently at odds with the “hardline” ayatollahs, has been calling for improved relations with Sunni nations.

“We want the rule of moderation and rationality in the relations between countries and we believe that a political solution should be a priority. The countries of the region need more cooperation and consultations to resolve the crisis in the region and we are ready to cooperate in this field,” Rouhani said during a telephone conversation with the Emir of Qatar.

Rouhani’s outreach to Qatar might be a little on the opportunistic side, since the emirate is currently experiencing a bit of turbulence in its relationships with Saudi Arabia, Egypt, and other major Saudi states. In fact, on Monday a minister from the United Arab Emirates described the rift as a “severe” crisis that could pose a “grave danger” to the future of the Gulf Cooperation Council.