Tensions between Saudi Arabia and Iran -- already running high -- could worsen with King Salman's designation of his assertive and ambitious son, Muhammad bin Salman, as the next ruler, analysts say.
Saudi Arabia's new crown prince and likely next king shares U.S. President Donald Trump's hard view of Iran, but a more confrontational approach toward Tehran carries a risk of escalation in an unstable region, current and former U.S. officials told Reuters.
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.
But for the last few years, Iranian rhetoric against Saudi Arabia has become almost a daily routine. From the Supreme Leader, Ali Khamenei down to military commanders and hardliners accuse the Saudis of supporting terrorism, being corrupt and sometimes call for the destruction of the House of Saud.
Iran's support for Houthis in Yemen has also been a stark challenge to Saudis in their own backyard.
The greatest danger for the Trump administration, a longtime U.S. government expert on Middle East affairs said, was for the United States to be dragged deeper into the Sunni-Shi’ite conflict playing out across the Middle East, a danger that could be compounded by Trump’s delegation of responsibility for military decisions to the Pentagon.
If the administration gives U.S. commanders greater authority to respond to Iranian air and naval provocations in the Gulf and Strait of Hormuz, things could easily spiral out of control, the official said.
"If we were to witness an incident at sea between an Iranian and a U.S. vessel in the Gulf, at a time of immense distrust and zero communication, how likely is it that the confrontation would be defused rather than exacerbated?" Reuters quotes Rob Malley, vice president for policy at the International Crisis Group.
"If there's a more bellicose attitude towards Iran, Iran is likely to respond," said Malley, a former senior adviser on Middle East affairs under President Barack Obama.
But Luke Coffey, director of the Foreign Policy Center at the Heritage Foundation, a conservative think tank, doubted Iran would retaliate in a major way.
"Iran has very limited ability or options to retaliate against U.S. forces in the region without suffering an overwhelming U.S. response," Coffey said.
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.