Tensions between Saudi Arabia and Iran -- already running high -- could worsen with King Salman's designation of his aggressive and ambitious son, Muhammad bin Salman, as the next ruler, analysts say.
The crown prince said last month on Saudi TV that he was not open to trying to improve relations with Tehran, which he accused of trying "to control the Islamic world" to spread its Shi'ite doctrine.
"We know we are a main target of Iran," the prince said, adding that conflict between the Sunni-led kingdom and Shi'ite-led Iran appeared inevitable.
"We will work so that it becomes a battle for them in Iran and not in Saudi Arabia," he said.
Those remarks raised alarm in Iran and helped fuel the widespread belief there that the Saudis were behind recent terrorist attacks in Tehran that were claimed by the Islamic State extremist group.
Iran's state media on June 21 called the prince's designation as the next Saudi ruler a "soft coup."
"Under his watch, Saudi Arabia has developed aggressive foreign policies in Yemen and Qatar, and he has not been shy about making strong statements against Iran," Olivier Jakob at the Petromatrix oil consultancy told Reuters.
"It is not really a question of if, but rather of when, a new escalation with Iran starts."
Petromatrix said the crown prince's designation was already contributing to a major slide in oil prices by raising doubt that the Saudis and Iran will be willing to cooperate in the future to curb production as they are today.
Based on reporting by AP and Reuters