Four months after ascending to the throne, Saudi Arabia’s King Salman on Wednesday signaled a toughening of Saudi policy toward Iran, firing the man he appointed only in January to succeed him and dumping the official who’d ruled the foreign policy of America’s most important Arab ally for 40 years.

The wide-ranging changes were announced at 4 a.m. in Saudi Arabia, lending an air of urgency to what was already a dramatic moment – the relieving of Prince Muqrin of his position as crown prince and deputy prime minister. In his place, the 79-year-old monarch named as his heir his nephew and the country’s interior minister, Prince Mohammed bin Nayef, 55. The king named his 30-year-old son and defense minister, Prince Mohammed bin Salman, as deputy crown prince.

Another casualty of Riyadh’s early morning reshuffle was the country’s foreign minister, Saud al-Faisal, who lost the job he’d held since 1975; he was replaced by the Saudi ambassador to the U.S., Adel al-Jubeir, who became the first non-royal to hold the post since 1962.

Similarly, another commoner, Ahmed al Sweilam, was appointed to the influential position of head of the royal court, making him a man to watch in Riyadh, analysts said.

The shakeup comes just weeks before Saudi Arabia and other members of the six-nation Gulf Cooperation Council are to meet with President Barack Obama in Washington and at Camp David, Md., on May 13-14, for what had been expected to be a discussion of the negotiations with Iran over its nuclear program.

The official announcement said that Muqrin, 69, had asked to be relieved of his responsibilities. But political analysts in the Persian Gulf said the decision to replace Muqrin, a former intelligence chief, was prompted by his opposition to the Saudi-led military campaign in Yemen, where Iranian-backed insurgents, the Houthis, have made huge advances since last fall.

The analysts noted, for example, that Muqrin did not host visiting Crown Prince Mohammed bin Zayed al Nahyan of the United Arab Emirates when he visited Saudi Arabia on Sunday, a major breach of protocol in the world of Gulf monarchies. Instead, the crown prince was conducted by Mohammed bin Salman, the defense minister and the new deputy crown prince. The UAE is part of the Saudi-led anti-Houthi alliance that has been bombing Yemen since March 26.

“Muqrin did not agree with the Yemen campaign (and) he tried to stay away from the Saudi-led alliance,” said Theodore Karasik, a Saudi-focused political analyst based in Dubai, in the United Arab Emirates. “Apparently, quick changes needed to be made to the succession line as a show of unity.”

The new deputy crown prince has been a champion of the Yemen campaign.

The reshuffle comes as the Saudi-led intervention in Yemen is about to transition from aerial bombings to Operation Restoring Hope, a name eerily similar to that of the United Nations’ ill-fated operation in Somalia from 1992 to 1994, which aims to restore Yemen’s ousted government and ease the humanitarian suffering caused by the conflict.

Saudi Arabia last week declared an end to its purely military campaign, saying it had achieved its goals of “removing the threat to Saudi Arabia and neighboring countries, especially in terms of heavy weapons.”

But the Saudi-led coalition has continued to bomb Yemen’s Houthi rebels and units of the Yemeni military loyal to ousted former President Ali Abdullah Saleh to prevent the rebels from seizing more territory.

“The hardest job yet of the Yemen project needs youth and vigor,” Karasik said. “With the generational change sped, the Saudis are showing the Middle East and the world that counterterrorism and nation-building are paramount.”

Analysts said the reshuffle in Saudi Arabia also signaled the kingdom’s intent to vigorously pursue its interests against Iran. Rhetoric against Iran has spiraled during the Yemen conflict to levels last seen in the 1980s, during the war between Iran and Iraq. The Gulf monarchies backed Iraq.

The analysts said the shift in Saudi thinking could be pinpointed to the moment, two years ago, when President Barack Obama decided against bombing Syrian President Bashar Assad’s forces after they used chemicals weapons in an attack on the outskirts of Damascus.

“This ‘shift’ in Saudi thinking has been in the works for a good two years,” said Fahad Nazer, a former political analyst at the Saudi Embassy in Washington; he now works as a terrorism experts at JTG Inc., a global intelligence adviser. “One could argue it was that moment that compelled the Saudis to adopt more proactive policies, in an attempt not to have to rely on the U.S. or any other country to safeguard their security interests.”

“I think the military campaign in Yemen demonstrates this new thinking in a dramatic fashion,” he said.

The appointment of younger, geopolitically ambitious leaders in Saudi Arabia matches a recent trend across the six-nation Gulf Cooperation Council. Mohammed bin Nayaf is the first grandson of Saudi Arabia’s founder, King Abdul-Aziz Al Saud, to be named heir apparent.

That matches the 53-year-old crown prince of the UAE, Mohammed bin Zayed al Nahyan, who met with Obama at the White House on April 20 and has worked closely with Saudi Arabia’s new deputy crown prince to prosecute the military campaign in Yemen, to which the UAE has contributed 30 of its 80 F-16 warplanes.

Another member of the coalition, Qatar, a leading global natural gas exporter, is ruled by 34-year-old Tamim bin Hamad al Thani, whose father stepped down in June 2013.

A rift developed between Qatar and its GCC neighbors in 2013 over its support for ousted Egyptian President Mohammed Morsi, but it was overcome last September after Qatar expelled members of Morsi’s Muslim Brotherhood.

Tamim has met with Saudi’s King Salman twice this year and has contributed 10 of Qatar’s French Mirage warplanes to the Yemen coalition.

“We are witnessing a further transition to a younger generation of GCC leaders who are more conservative in their outlook and willing to use force, if necessary, to protect their monarchies from both state and non-state actors,” Karasik said.