If we didn't know it before, the upsurge in global protest in the past couple of years has driven home the lesson that mass demonstrations can have entirely different social and political meanings. Just because they wear bandannas and build barricades – and have genuine grievances – doesn't automatically mean protesters are fighting for democracy or social justice.

From Ukraine to Thailand and Egypt to Venezuela, large-scale protests have aimed at, or succeeded in, ousting elected governments in the past year. In some countries, mass protests have been led by working class organisations, targeting austerity and corporate power. In others, predominantly middle class unrest has been the lever to restore ousted elites.

Sometimes, in the absence of political organisation, they can straddle the two. But whoever they represent, they tend to look similar on TV. And so effective have street demonstrations been in changing governments over the past 25 years that global powers have piled into the protest business in a major way.

From the overthrow of the elected Mossadegh government in Iran in the 1950s, when the CIA and MI6 paid anti-government demonstrators, the US and its allies have led the field: sponsoring "colour revolutions", funding client NGOs and training student activists, fuelling social media protest and denouncing – or ignoring – violent police crackdowns as it suits them.

And after a period when they preened themselves on promoting democracy, they are reverting to their anti-democratic ways. Take Venezuela, which for the past two months has been racked by anti-government protests aimed at overthrowing the socialist government of Nicolas Maduro, elected president last year to succeed Hugo Chávez.

The rightwing Venezuelan opposition has long had a problem with the democracy business, having lost 18 out of 19 elections or referendums since Chávez was first elected in 1998 – in an electoral process described by former US president Jimmy Carter as "the best in the world". Their hopes were raised last April when the opposition candidate lost to Maduro by only 1.5%. But in December, nationwide elections gave the Chavista coalition a 10-point lead.

So the following month, US-linked opposition leaders – several of whom were involved in the failed US-backed coup against Chávez in 2002 – launched a campaign to oust Maduro, calling on their supporters to "light up the streets with struggle". With high inflation, violent crime and shortages of basic goods, there was plenty to fuel the campaign – and protesters responded, literally.

For eight weeks, they have burned universities, public buildings and bus stations, while up to 39 people have died. Despite claims by the US secretary of state, John Kerry, that the government is waging a "terror campaign" against its citizens, the evidence suggests a majority have been killed by opposition supporters, including eight members of the security forces and three motorcyclists garrotted by wire strung across street barricades. Four opposition supporters have been killed by police, for which several officers have been arrested.

What are portrayed as peaceful protests have all the hallmarks of an anti-democratic rebellion, shot through with class privilege and racism. Overwhelmingly middle class and confined to wealthy white areas, the protests have now shrunk to firebombings and ritual fights with the police, while parts of the opposition have agreed to peace talks.

Support for the government, meanwhile, remains solid in working class areas. As Anacauna Marin, a local activist in the 23 January barrio in Caracas puts it: "Historically protests are a way for the poor to demand an improvement in their conditions. But here the rich are protesting and the poor are working."

It's hardly surprising in the circumstances that Maduro regards what's been going on as Ukraine-style US-backed destabilisation, as he told me. The US claim that this is an unfounded "excuse" is absurd. Evidence for the US subversion of Venezuela – from the 2002 coup through WikiLeaks-revealed cables outlining US plans to "penetrate", "isolate" and "divide" the Venezuelan government, to continuing large-scale funding of opposition groups – is voluminous.

That's not only because Venezuela sits on the world's largest oil reserves, but because it has spearheaded the progressive tide that has swept Latin America over the past decade: challenging US domination, taking back resources from corporate control and redistributing wealth and power. Despite its current economic problems, revolutionary Venezuela's achievements are indisputable.

Since regaining control of its oil, Venezuela has used it to slash poverty by half and extreme poverty by 70%, massively expanded public health, housing, education and women's rights, boosted pensions and the minimum wage, established tens of thousands of co-ops and public enterprises, put resources in the hands of a grassroots participatory democracy, and funded health and development programmes across Latin American and the Caribbean.

So it's not surprising that Maduro's Chavistas still have majority support. To maintain that, the government will have to get a grip on shortages and inflation – which it has the means to do. Prices spiked after it cut the supply of dollars to the private sector, which dominates food imports and supply, while a large proportion of price-controlled goods are smuggled into Colombia to sell at far higher prices.

A recent easing of currency controls has already had an impact. For all its problems, the economy has continued to grow and unemployment and poverty fall. Venezuela is very far from being the basket case of its enemies' hopes. But the risk is that as the protests run out of steam, sections of the opposition turn to greater violence to compensate for their failure at the ballot box.

Venezuela and its progressive allies in Latin America matter to the rest of the world – not because they offer a ready-made political and economic model, but because they have demonstrated that there are multiple social and economic alternatives to the failed neoliberal system that still has the west and its allies in its grip.

Their opponents hope that the impetus for regional change has exhausted itself with Chávez's death. The recent election of the left-leaning Michelle Bachelet in Chile and the former leftwing rebel leader Sánchez Cerén in El Salvador suggests the tide is still flowing. But powerful interests at home and abroad are determined that it fails – which means there will be more Venezuela-style protests to come.

Twitter: @SeumasMilne