In the wake of the May 19 passing of Iranian President Ebrahim Raisi and Foreign Minister Hossein Amir-Abdollahian in a helicopter crash near the border with Azerbaijan, the heads of Arab countries and non-state actors alike have expressed sympathy with Tehran.

Some of the reactions, including from countries such as Egypt and Saudi Arabia, reflect Raisi’s focus on fostering improved relations with Iran’s neighbors as his top foreign policy priority. Moreover, as the late president and his companions will be laid to rest, the Islamic Republic is set to host a number of...