A top U.S. military officer claimed on Monday that the growing diplomatic feud between arch rivals Saudi Arabia and Iran serves as a reminder of the volatile sectarian rifts that threaten security in the Middle East, according to Stars and Stripes.

“To the extent that sectarianism is a source of instability, clearly we are concerned about the announcement Saudi Arabia is breaking off relations with Iran,” Gen. Joseph Dunford, chairman of the Joint Chiefs, said. “We’re looking pretty hard at what the implications are of this decision.”

Dunford, who spoke with reporters in Stuttgart, Germany, after meetings at the headquarters of the U.S. European and Africa Commands, said it was too early to draw any military conclusions from the dispute between Saudi Arabia and Iran. Saudi Arabia’s execution of Shiite cleric Nimr Al-Nimr, a prominent advocate for the country’s Shiite minority and an anti-government critic, sparked demonstrations across the region.

“The challenge in the Middle East that has gotten the most attention has been ISIL,” Dunford said, using an acronym for the Islamic State group. “But clearly the sectarian challenges in the Middle East were there before ISIL, and those are the ones highlighted by the announcement of Saudi Arabia breaking off relations with Iran.”