The story: Russian security chief Sergei Shoigu has visited Tehran for talks with top officials, raising eyebrows given the growing tensions between Iran and Israel. Already, reports charge that Moscow has begun delivering air defense equipment and advanced radars allegedly requested by the Islamic Republic.

The visit comes as Iran and its regional allies weigh the scale of their response to Israel’s suspected assassination of Hamas political bureau chief Ismail Haniyeh. Iran has pledged to avenge the July 31 killing of Haniyeh in Tehran as the region braces for escalation.

The Russian visit: Shoigu, the secretary of Russia’s Security Council, landed in Tehran on Aug. 5 on what Russian media described as a...