Ordinary Russians are sharply divided over Vladimir Putin's military manoeuvres in Crimea in recent days, with competing rallies in Moscow and furious arguments on social media.

But experts say most people will probably support the government line, since a majority views Crimea as part of Russia – and the transfer of power in Ukraine as a western-backed coup.

Denis Volkov, of the independent polling organisation Levada Centre, said that although in the past most Russians opposed military intervention in other countries, the fact that no open conflict had broken out in Crimea thus far made the Russian move easier to justify.

"Many see Putin as the one who returned some of Russia's strengths [after the Soviet breakup], and I think he will use this idea of the loss of the Soviet Union to drum up support with Crimea," Volkov said.

While Angela Merkel said at the weekend that Putin was not in touch with reality, many Russians would disagree. The latest Levada poll conducted from 21-25 February found that most Russians regard the new government in Kiev negatively: 43% called the political upheaval in Ukraine a "violent coup" and 23% called it a civil war.

Moreover, 45% blamed western influence for bringing people on to the streets of Kiev, where the "Euromaidan" protests that were originally in favour of further European integration later turned into a general condemnation of the corrupt regime.

A September poll by the state-run survey centre VTsIOM found that 56% of Russians considered Crimea, which Russia seized from the Tatars in the 18th century, to be a part of Russia. The Soviet leader Nikita Khrushchev gave the territory to Ukraine in 1954, but ethnic Russians still make up 59% of Crimea's population of 2 million, while 12% are Tatars, according to 2001 census data.

An informal Facebook poll this weekend asking whether the Russian military should be intervening in Crimea drew heated arguments from both sides and descended into debaters accusing each other of illiteracy and treason.

"If soldiers hadn't showed up in Crimea, things could have escalated into Russian-Tatar pogroms," Alexander Zheleznyak, a Moscow-based travel journalist who grew up in the Crimea, told the Guardian.

"No matter what you think of Putin, right now he's taken the responsibility on himself and stopped senseless beatings in Crimea," Zheleznyak said, referring to reports that two people died in clashes between rival pro-Russian and Tatar activists outside the Crimean parliament last week.

Masha Lipman, of the Carnegie Moscow Centre, said that for most Russians, the perception that "anti-Russian nationalists and fascists took power leads to the feeling that we need to save and protect our own."

Few people were thinking of the geopolitical implications as Putin struggles against the integration of Ukraine, a key ally, with the European Union and the possible eastwards expansion of Nato, she said.

"We assume that Putin wants revenge for this, that he's not ready to make peace with this move, and achieving superiority is extremely important for him," she said.

Hundreds gathered on Sunday in central Moscow under the slogan "No to war!" but were overshadowed by a larger protest to support "the brother people of Ukraine", where some attendees were accused of being paid to participate. Police broke up the peace rally and detained 361 people

"We need to protect people from fascism, from evil. We support Putin," Dmitry Enteo, a Russian Orthodox activist, told people at the pro-government rally, the independent newspaper Novaya Gazeta reported.