Belgians are being told that they need to increase their consumption of fries. Across Britain, farmers have dumped millions of pints of milk down the drain instead of churning it into butter. In Iran, millions of baby chickens - which may have one day been bound for barbecues - have been buried alive. In India, farmers are feeding strawberries to cattle rather than sending them to markets.

Is this what an "efficient" global food system looks like?

According to the economists, politicians and corporations that have pushed for increasingly interconnected food supply chains over the past 50 years, efficient is what it's supposed to be: Each country specialises in what it's best at - potatoes in Belgium, beef in Canada, cocoa in Ghana - and puts the produce on the global market.

Producers and processors within countries specialise, too, as a way to minimise costs. As a result, at least in theory, prices stay low, the world gets fed and everyone wins. The coronavirus has revealed that there are serious weaknesses with relying too much on this approach.

Improving efficiency can certainly be a good thing, especially if consumers benefit from cost savings and access to more diverse foods. But the changes in recent years have undermined other important goals, like the ability to adapt during a crisis.

When new barriers prevent food from reaching its markets, or demand suddenly drops - both of which are happening now - the system falls apart.

The current breakdown is the product of multiple disruptions that the food system is ill-equipped for: lockdowns, closed borders, trade curbs and the virus itself. Any one of these would have caused problems in the world's complex and specialised food supply chains. All of them happening at the same time is wreaking havoc.

Global trade in food dates back centuries - ancient Romans traded wine across the Mediterranean; spices travelled the Silk Road, but since the 1970s, when agricultural industrialisation began to speed up, more and more people have relied on another country for providing at least part of their meals.

International food trade has increased nearly fivefold since the 1990s, when governments agreed to new rules to open up food trade. Today, nearly a quarter of all food produced crosses a border.

Large transnational corporations saw an opportunity to profit from these changes and are now pivotal players in the trade, processing and packaging of food. As we have seen with the emergence of mega-sized companies that dominate entire sectors in the rest of the economy, the largest of the food and agriculture businesses have been buying up their rivals in recent years and command huge power.

These changes fundamentally transformed food systems that once were more localised and diverse to be more specialised, distant and corporate controlled. Farmers increasingly contract to produce single commodities - crops, meat, dairy - for just a few large transnational corporate buyers that process and market it.

A food system organised in this way may be "efficient" in terms of delivering lower prices, but it also has costs: to the environment, to social inequality and, as the pandemic has revealed, to flexibility in the face of disruption.

Specialisation makes it hard to shift into different markets when disruptions arise. Belgium, one of the world's leading exporters of potatoes, lost sales not only to local shuttered restaurants but also to other European countries and China because of lockdowns. At least the Belgians can try to eat the potatoes at home.

That strategy won't work for every crop: Ivory Coast and Ghana, the world's top two cocoa exporters, lost markets across Europe and Asia when people started focusing on buying essential items during the lockdowns instead of chocolate.

The loss in export income in Africa more generally could have huge ramifications if the pandemic continues, as many countries on the continent rely heavily on rice and wheat imports. The prices of these grains have soared not only because of rising demand for these staple grains during the crisis, but also because a few countries imposed export curbs out of fear that sending food abroad would lead to higher prices at home.

Concentrated markets dominated by just a handful of companies create narrow bottlenecks that heighten food system fragility. The meat packing industry is one of the most concentrated in the United States, and in many other countries.

In Canada, just three meat packing plants process over 95 per cent of the country's beef and nearly all of its beef exports. In both the US and Canada, meat processing plants have had to close temporarily because of outbreaks of Covid-19 among their workers.

The meat packing disruptions also highlight other consequences of the food system's drive for efficiency: its reliance on poorly treated workers, many of whom are immigrants and people of colour, and its dependence on seasonal migrant labour, as evidenced by the fact that travel shutdowns have led to widespread labour shortages across Europe and North America.

And this isn't just about justice, as important as that is: If the people who keep food supply chains moving are made vulnerable by unsafe working conditions, low wages and closed borders, the entire food system is vulnerable.

Seeing the spoiled dairy products, rotten vegetables and needlessly culled animals should force all of us to rethink our "efficient" food supplies and try to create a system that is better able to withstand shocks.

We need to rejuvenate local and regional food systems to reduce the vulnerabilities that come with being too reliant on imported and corporate-dominated foods. This doesn't mean cutting off all trade or abolishing all packaged foods, but it does mean building diversity, decent livelihoods for workers and opportunities for small and medium-scale firms to flourish in shorter, more sustainable supply chains that are closer to home.

One place to start is for governments to shift their support from the large-scale, specialised and export-oriented food system to building infrastructure for more diverse local food production, processing and markets.

In North America and elsewhere, small-scale and organic producers have been overwhelmed with the surge in interest from customers who want to buy directly from farmers during this virus crisis. But these producers often lack the infrastructure to meet that growing demand.

As governments around the world pass stimulus packages to address the crisis, building more diverse and localised food systems should be an obvious inclusion.

For decades, alternative food movements promoting local markets and sustainable production methods have sought to expand their reach in the face of growing social inequities and a changing climate. But lower prices and abundant supply offered by the global food system were serious headwinds. Now that the pandemic has shown just how fragile that system is, it is time to seize the moment to build real change that prioritises diversity and resilience.

NYTIMES.

• Jennifer Clapp is a professor in the School of Environment, Resources and Sustainability at the University of Waterloo in Ontario and the author, most recently, of Food.