The escalating conflict in the Middle East is fueling fears that Washington's pursuit of regime change in Iran, and Tehran's retaliation, could destabilize regions from the Gulf to Europe, leaving global leaders scrambling to assess the fallout.

The U.S. and Israel launched joint strikes on Iran over the weekend, killing the Islamic Republic's Supreme Leader Ayatollah Ali Khamenei, prompting waves of attacks by Tehran across the region.

President Donald Trump made it clear in a video message Saturday following the initial wave of U.S.-Israel strikes on Iran that his objective was "eliminating imminent threats from the Iranian regime, a vicious group of very hard, terrible people."

Geopolitical analysts warned that Saturday's strikes could be the opening salvo of a sustained military campaign aimed at dismantling the Iranian regime, with the U.S. seeking to assert dominance over the world's most critical oil-producing region.

"The scale of the strikes by the U.S. and Israel, along with the apparent goal of regime change in Iran, suggest the military conflict could escalate rapidly and unpredictably," said Rexon Ryu, President of The Asia Group, a business consultancy firm. "There is substantial immediate risk for regional and potentially global escalation, as Iran may now use any available option to respond."

"The previous strikes were targeted at the nuclear weapons program," said David Silbey, a professor of military history at Cornell University, referring to the 12-day war in June last year when the U.S. and Israel launched air strikes that damaged three key Iranian nuclear sites.

But "this one will be much broader, aimed at command and control, headquarters and leadership, and the military and secret police generally," said Silbey. "Since there doesn't seem to be a U.S. ground campaign in the offing, the goal is to get the regime overthrown domestically, either by a popular uprising or a palace coup."

Silbey warned that Iran could respond with retaliatory attacks, including missile strikes on Israeli and U.S. military bases and vessels in the Persian Gulf, as well as potential terrorist operations across the Middle East, Europe and the United States.

"If the regime feels threatened, it'll lash out harder than it would if it thought it could ride out the attacks," Silbey said.

The latest conflagration has already spread to other parts of the Gulf region. Iranian missiles targeted Israel and multiple Gulf states, including the UAE, Qatar, Bahrain, Saudi Arabia, Kuwait and Jordan, all countries with air bases containing U.S. assets.

"Years of Iranian détente-building with the Gulf may be over," said Aysha Chowdhry, principal at The Asia Group.

Both Russia and China have offered statements condemning the U.S., and that will likely continue to be the case even as the situation escalates, but analysts say neither is in a position to give more meaningful material support.

China, a critical economic lifeline for Iran amid heavy Western sanctions, purchased more than 80% of Tehran's shipped oil in 2025, accounting for 13.5% of all crude China imported by sea. Iran has also been a vital supplier of military drones and missiles to aid Moscow's warfare efforts in Ukraine.

But years of grinding war in Ukraine have hollowed out Russia's capacity to project power beyond its borders, said Matt Gerken, chief geopolitical strategist at BCA Research.

With its military overstretched and its economy under sustained pressure from Western sanctions, Moscow's influence in the Middle East is set to diminish further, Gerken added.

But Beijing has refrained from coming out in strong support of Iran as Washington continued to build up its military presence in the Gulf in the lead up to the attack. Instead, it has focused on encouraging diplomacy and regional security.

Analysts are watching for potential signs of whether this latest Middle East conflict could risk derailing the U.S.-China diplomatic engagement and even President Trump's planned visit to Beijing later this month.

In a statement Saturday night, a spokesperson for China's foreign ministry urged the U.S. and Israel to "immediately stop military actions" in the region and restore dialogues, calling for "respect of Iran's sovereignty, security and territorial integrity."

Trump and Chinese president Xi Jinping discussed issues including Iran, Taiwan and trade in a phone call on Feb .4. "Beijing may seek concessions on issues more directly related to its interests, such as Taiwan and trade, in exchange for its significantly watered-down messaging on Iran," said Ahmed Aboudouh, a fellow at Chatham House, a London-based policy think tank.

A weakened Iran, paradoxically, may suit Chinese interests. "The weaker the Iranian regime gets, whether from U.S. or Israeli military strikes or domestic unrest, the more diplomatically, economically and technologically dependent on China it will become," said Aboudouh.

For the longer term, China will likely feel pressure to assert dominance in the region. "China will need to make a demonstration of power projection in its region to deter American military action and create a sphere of influence," though for now, oil supply vulnerabilities may limit its options, Aboudouh said.

The military actions appeared to have have, at least for now, shattered any remaining prospect of a negotiated settlement over Iran's nuclear program.

The U.S. and Iran had engaged in three rounds of indirect talks with a focus on reaching a deal on Iran's nuclear and ballistic missile programs and Washington lifting economic sanctions on the country.

With Iran's regime at a moment of "critical vulnerability," Washington and Jerusalem were unable to get guarantees of denuclearization and disarmament from Tehran and decided that they "could not afford to miss the opportunity to reshape the region," Gerken said.