ANALYSIS - Israel's attacks on Iran hint at a bigger ambition: regime change

But the scale of the attacks, Israel's choice of targets, and its politicians' own words suggest another, longer-term ambition: toppling the regime itself.

The strikes early on Friday hit not just Iran's nuclear facilities and missile factories but also key figures in the country's military chain of command and its nuclear scientists, blows that appear aimed at diminishing Iran's credibility both at home and among its allies in the region - factors that could destabilize the Iranian leadership, experts said.

"One assumes that one of the reasons that Israel is doing that is that they're hoping to see regime change," said Michael Singh of the Washington Institute for Near East Policy and a former senior official under President George W. Bush.

"It would like to see the people of Iran rise up," he said, adding that the limited civilian casualties in the initial round of attacks also spoke to a broader aim.

In a video address hours after Israeli fighter jets began striking Iranian nuclear facilities and air defence systems, Israel's prime minister, Benjamin Netanyahu, appealed to the Iranian people directly.

"The Islamic regime, which has oppressed you for almost 50 years, threatens to destroy our country, the State of Israel," Netanyahu said.

Israel's objective was to remove the nuclear and ballistic missile threat, he said, but added: "As we achieve our objective, we are also clearing the path for you to achieve your freedom.

"The regime does not know what hit them, or what will hit them. It has never been weaker. This is your opportunity to stand up and let your voices be heard," Netanyahu said.

But despite the damage inflicted by the unprecedented Israeli attack, decades of enmity toward Israel - not only among Iran's rulers but its majority-Shi'ite population - raises questions about the prospect for fomenting enough public support to oust an entrenched theocratic leadership in Tehran backed by loyal security forces.

Singh cautioned that no one knows what conditions would be required for an opposition to coalesce in Iran.

Friday's assault was the first phase of what Israel said would be a prolonged operation. Experts said they expected Israel would continue to go after key Iranian nuclear infrastructure to delay Tehran's march to a nuclear bomb - even if Israel on its own does not have the capability to eliminate Iran's nuclear program.

Iran says its nuclear programme is for civilian purposes only. The U.N. nuclear watchdog concluded this week that it was in violation of its obligations under the global non-proliferation treaty.

Israel's first salvoes targeted senior figures in Iran's military and scientific establishment, took out much of the country's air defence system and destroyed the above-ground enrichment plant at Iran's nuclear site.

"As a democratic country, the State of Israel believes that it is up to the people of a country to shape their national politics, and choose their government," the Israeli embassy in Washington told Reuters. "The future of Iran can only be determined by the Iranian people."

Netanyahu has called for a change in Iran's government, including in September.

U.S. President Donald Trump's administration, while acquiescing to Israel's strikes and helping its close ally fend off Iran's retaliatory missile barrage, has given no indication that it seeks regime change in Tehran.

The White House and Iran's mission to the United Nations in New York also did not immediately respond to requests for comment on the matter.

ENDING NUCLEAR PROGRAMME BEYOND REACH, FOR NOW

Israel has much further to go if it is to dismantle Iran's nuclear facilities, and military analysts have always said it might be impossible to totally disable the well-fortified sites dotted around Iran.

The Israeli government has also cautioned that Iran's nuclear programme could not be entirely destroyed by means of a military campaign.

"There's no way to destroy a nuclear programme by military means," Israel's National Security Adviser Tzachi Hanegbi told Israel's Channel 13 TV. The military campaign could, however, create conditions for a deal with the United States that would thwart the nuclear programme.

Analysts also remain sceptical that Israel will have the munitions needed to obliterate Iran's nuclear project on its own.

"Israel probably cannot take out completely the nuclear project on its own without the American participation," Sima Shine, a former chief Mossad analyst and now a researcher at Israel's Institute for National Security Studies, told reporters on Friday.

While setting back Tehran's nuclear programme would have value for Israel, the hope for undermining the regime could explain why Israel went after so many senior military figures, potentially throwing the Iranian security establishment into confusion and chaos.

"These people were very vital, very knowledgeable, many years in their jobs, and they were a very important component of the stability of the regime, specifically the security stability of the regime," said Shine.

"In the ideal world, Israel would prefer to see a change of regime, no question about that," she said.

But such a change would come with risk, said Jonathan Panikoff, a former U.S. deputy national intelligence officer for the Middle East who is now at the Atlantic Council.

If Israel succeeds in removing Iran's leadership, there is no guarantee the successor that emerges would not be even more hardline in pursuit of conflict with Israel.

"For years, many in Israel have insisted that regime change in Iran would prompt a new and better day - that nothing could be worse than the current theocratic regime," Panikoff said. "But history tells us it can always be worse."