Saudi Arabia's ruler used to be one of Trump's biggest fans. This time it's complicated.

• Saudi leader Mohammed bin Salman welcomed Donald Trump's first election win.
• But this time round, Gulf leaders may be wary about his victory.

Donald Trump's first trip as US president to Saudi Arabia in 2017 was a lavish spectacle.

He joined a traditional sword dance, had his image projected onto the Ritz Carlton in Riyadh, and signed a multibillion-dollar arms deal with the kingdom.

At the time, leaders like Saudi Arabia's Crown Prince Mohammed bin Salman lavished praise on him and welcomed his brash style, particularly toward Iran.

Now, however, attitudes toward Iran have changed, and Gulf leaders' reactions to Trump's reelection as US president will likely be less enthusiastic.

"Gulf Arab states have concerns about Trump being unpredictable and the risks of having him back in the White House," Giorgio Cafiero, CEO of consultancy Gulf State Analytics, told Business Insider.

Of particular concern, said Cafiero, is the fear that Trump could inflame the Middle East at a time when it is on the brink of all-out regional war.

The Middle East on the brink

The threat of an all-out regional war in the Middle East was triggered by Hamas terrorist attacks on Israel on October 7, 2023.

In response, Israel has sought to destroy Hamas and its ally, the Lebanese militia Hezbollah.

It's launched attacks on Gaza and Lebanon that have devastated the Iran-backed groups and resulted in tens of thousands of civilian casualties.

The war could escalate into a direct conflict between Israel and Iran, with Iran launching missile attacks on Israel twice this year, and Israel responding with strikes on targets in the Islamic Republic.

President Joe Biden provided military backing to Israel after October 7 and tried to persuade its prime minister, Benjamin Netanyahu, to scale back Israel's response.

Trump, during his term in office, backed controversial Israeli policies such as West Bank settlements and had a warm relationship with Netanyahu.

Some in the region are concerned he'd offer Israel even stronger support for its wars than Biden, said Cafiero.

"His first administration had a highly Israel-centered foreign policy in the region and there are many open questions about how he'll approach the wars in Gaza and Lebanon after his second term begins in January 2025," he added.

MBS is likely wary

Saudi's ruler, Crown Prince Mohammed, is increasingly wary that the war between Israel and Iran's network of regional militias could escalate further, pulling in the kingdom and other Gulf states.

The region is a patchwork of allegiances, with the Gulf states and Israel broadly aligned with the US while Iran is aligned with Vladimir Putin's Russia.

In September, Iran, through backchannels, warned Saudi leaders that the kingdom's energy sector would be targeted if it allowed Israel to use Saudi airspace for attacks on Iranian oil or nuclear sites.

"How Trump will go about addressing such disagreements is unclear, but his unpredictable nature must be causing some policymakers in the GCC [Gulf Cooperation Council] to have some concerns about what it will be like working with his second administration," said Cafiero.

Mahjoob Zweiri, a fellow at the Middle East Council on Global Affairs, said that world leaders have to realize that Trump is not the same man he was during his first presidency.

"His time in power has changed him, and his approach has evolved," he said. "Another significant point is his naturally rebellious political stance, which challenges the conventional norms of both domestic and foreign policy.

"In other words, he has a strong, personal perspective on events, and he imposes it."

A fragile peace

Amid growing tensions, Crown Prince Mohammed has been trying to maintain Saudi Arabia's fragile truce with Iran.

In 2023, China brokered a resumption in diplomatic relations between the longtime regional foes that have held despite the new wave of conflict sweeping the region.

The Saudi ruler on Monday hosted Muslim leaders in Riyadh, where, according to reports, he described Israel's attacks on Palestinian civilians as a "genocide" and condemned its attacks on Iran.

Both Trump and Biden had sought to broker a deal to normalize ties between Saudi Arabia and Israel, but the future of the deal appears at best uncertain amid regional hostility to Israel's campaign.

Analysts say Crown Prince Mohammed believes that tamping down regional conflict is crucial for achieving his grand ambitions of transforming Saudi Arabia's economy as part of his Vision 2030 Project.

He's also concerned about potential Iranian ballistic missile attacks, and domestic anger at Israel in Saudi Arabia, executive vice president of the Washington, DC-based Quincy Institute Trita Parsi told CNN.

"Now that there is much uncertainty in the region with direct Iran-Israel confrontations moving toward a point of becoming increasingly normalized, and the Trump 2.0 factor, Riyadh and Tehran have been signaling to each other that they remain committed to the Beijing-brokered diplomatic deal," said Cafiero.

If the Iran-Israel confrontation intensifies and the US gets pulled in, it's unclear if Trump would respect Saudi Arabia's wish to remain on the sidelines.

"If Trump puts you in a situation where you have to decide [which side to take] because he's going against Iran, it's a big problem," a senior Arab diplomat told The Financial Times this week. "Trump is not the kind of guy who takes 'no' for an answer."