The astonishing killing of Bolivia's Deputy Interior Minister Rodolfo Illanes by striking miners has, not for the first time, pitted the government headed by Evo Morales against the country's social movements. The minister's death follows the killing of protesting miners by police.

Part of the shock is that Morales' government came to power after insurrectionary social conflicts in which his movement of coca growers allied with miners and other groups of workers fought with the government and multinational firms.

Now Morales accuses his former allies of "political conspiracy" and cowardice, lauding the dead minister as a martyr for national resources.

Turning tide

Morales' resort to conspiracy theory makes a certain sense in the context of Latin America, where a series of left-wing governments elected as part of a "pink tide" in the 2000s have gone into crisis.

Argentina elected its first right-wing government in 12 years in November. Venezuela's economic crash has led to the victory of the right-wing opposition in the senate. Notwithstanding the hyperventilating coverage of the country's "total collapse", the country is beset by real problems, with a combination of opposition disruption, international pressure and government mistakes exacerbating the turmoil.

Even in Brazil, where the government of Dilma Rousseff was re-elected, impeachment proceedings have put the unelected opposition in power.

Rousseff is impeached for manipulating the figures to make the government's finances look better than they were, but the real problem appears to be that amid economic troubles, Rousseff was elected on a programme of investment rather than austerity.

And although she had promised to impose austerity, investors didn't trust that she would. The programme of the newly empowered opposition, says the Financial Times, "reads like a wishlist for markets and investors".

With global stagnation and falling export prices, the 'pink tide' states must choose between their social programme and their economic strategy.

Bolivia has until recently been the exception to this pattern. After 2012, its economy boomed with growth rates of more than 6 percent. Even after growth stabilised at 3.5 percent, this left Bolivia outperforming the other "pink tide" states.

It had achieved all this against free market orthodoxy, with the highest level of public investment in the region. With high economic growth, the government has been able to introduce minimum wage rises much higher than the rate of inflation.

For left-wing commentators, Bolivia has stood as an example of how leftist governments can use economic policy to advance socialism, without damaging capitalist growth.

Failing to break the fundamentals

So why has this spectacular outburst of violence taken place in Bolivia? Until recently, the cracks appearing in Morales' coalition have been relatively small.

But in addition to the social movements, the government has built its authority on support from the police and army. And it has repeatedly deployed police against social movements where they were inconvenient, such as during the protests against fuel price increases in 2010, or against a road built on indigenous land during 2011.

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In the past year, the government came under increasing pressure as mineral prices fell precipitously, and the country's credit rating was cut in response to its growing need for borrowing.

The current explosion of outrage from miners reflects the fact that they have been the first to suffer from declining metal prices, and the first to suffer from police repression when they protested.

These tremors bring to the fore the existing limitations of Morales' model. He has been unable to break with the fundamentals of the economic system he inherited.

The "nationalisation" of hydrocarbons still left 12 energy companies exploiting the resources for export. The "cooperatives" in the mining industry are no such thing and the position of the workers is largely precarious.

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The economy still depends upon the export of primary goods, and the government still depends on the acquiescence of the Santa Cruz-based business class, which it retains by adhering to Washington-backed fiscal discipline and tight monetary policy to control inflation.

Spin aside, Morales has failed to deliver the most important demands of the social movements.

Rethinking for progressive change

Nonetheless, in an era of relative plenty, with high international growth, trade and commodity prices, this worked.

Business could profit, the state could run surpluses, and workers could be paid off all at once, without major encroachments on the ownership of wealth.

This is the classic social-democratic formula, and Bolivia was able to keep it going for a period of time despite the global downturn. Much of the global left looked on in admiration.

Yet, with global stagnation and falling export prices, the "pink tide" states must choose between their social programme and their economic strategy.

To defend their social goals and keep the movements onside, they may need to risk encroaching on the profits and rights of investors.

And as we are seeing in Brazil and Venezuela, they won't give up those privileges without a fight. The international left may need to think hard about its model for progressive change.

Richard Seymour is an author and broadcaster based in London. He has written for The Guardian, the London Review of Books and many other publications.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.