With the Great Satan (aka America) being secretly behind it.

Via JPost:

Iranian Supreme Leader Ayatollah Ali Khamenei slammed Saudi Arabia on Monday for allegedly tightening its ties with Israel.

“Revelation of Saudi government’s relations with Zionist regime was stab in the back of Islamic Ummah,” Khamenei tweeted.

Khamenei suggested that the Saudi move to warm up to Israel, as well as the Kingdom’s involvement in Yemen’s conflict, were being guided by the United States.

“Today, #Saudi government is in hands of unwise people, but close scrutiny shows US hands are behind all these issues,” he tweeted.