American soyabean farmers could draw some comfort from the tariffs that China imposed on an array of American imports on February 10th. Foodstuffs like theirs were not affected by China’s countermeasures against the 10% levy on Chinese imports that had been ordered a few days earlier by President Donald Trump. But growers in farming states like Illinois and Iowa still have reason to worry. China’s leader, Xi Jinping, wants to wean his country off food from the West. Amid rising geopolitical tensions, he sees self-sufficiency and diversity of supply as an increasingly urgent need.

In Mr Xi’s calculations, much has changed since Mr Trump launched his first trade war against China in 2018, during his previous term in the White House. American soyabeans—which China imports mainly for feeding farm animals—were then a prime target. China slapped tariffs of up to 25% on American farm products. Its state media highlighted the impact this would have on Mr Trump’s rural supporters. The pain was felt less in China: it turned much more to Brazil instead. The tariffs were mostly removed in 2019, but Mr Xi had made his point. China—which previously had imported 40% of its foreign soyabeans from America—no longer had to rely so heavily on it.

Since then, the People’s Republic has gained yet more leverage. America now provides less than one-fifth of the soyabeans that China buys from abroad. For American soyabean farmers, China remains nearly as important as it was: it still takes nearly half of their exports (down from just over 60% in 2017). But for Mr Xi, any dependence on the West remains uncomfortable. In the past few years, as the contest with America and other Western countries has intensified, China has become ever more preoccupied with maintaining food security, stressing that it is a vital component of national security. In 2023 China published a book of Mr Xi’s thoughts on the topic. Last year the country introduced its first food-security law.

All this has expanded the way China views food security. The usual term for it is liangshi anquan, which literally means grain security. It commonly refers mainly to rice, wheat and maize as well as soyabeans (an oilseed). Now it is promoted with another term: da shiwu guan, or the “big food concept”, covering all types of commonly eaten foodstuffs. “We cannot allow others to control us! This is a major matter of national security!” Mr Xi told rural-affairs officials in December 2020.

Yanking your supply chain

That year China experienced the first of two global shocks that focused its attention on food (after an outbreak of swine flu that in 2019 cut swathes through the country’s pig stocks). During the covid-19 pandemic, stockpiling, poor harvests and disruption to shipping caused global prices of farm produce to surge, sounding a warning bell in China. Then in 2022 came the Russian invasion of Ukraine, an agricultural giant. The country accounted for over a quarter of China’s imports of maize and barley. The impact on food supply in China was mild: stockpiles enabled the country to stabilise prices, and it found other sources. But the war highlighted the vulnerability of global supply chains. In a conflict with America over Taiwan, say, many of China’s imports, including food, would be imperilled.

That could be a serious blow to China. The country is the world’s biggest producer of food. Its grain harvest last year (including soyabeans) hit a record high of more than 706m tonnes. It is over 95% self-sufficient in the production of main staples for human consumption: rice and wheat. But the country’s growing wealth has fuelled demand for a much more varied diet. Since 2004 China has been a net importer of foodstuffs. It is now the world’s biggest buyer of them. Imports in 2023 were worth $140bn. It relies on foreign supplies for 80% of its soyabean needs, 70% of its edible oils, 30% of its milk and nearly 10% of its meat (see charts).

Xi’s cheese

Mr Xi worries about all this. He sees a robust agricultural economy as a great-power necessity. In 2013 he said that the strength of countries like America, Russia, Canada and Europe’s major powers was “closely linked with their capacity to produce grain”. He does not say China should aim to end all imports, but declared in 2019 that “Chinese people’s rice bowls should mainly be filled by their own food. That includes the main non-staples.”

To boost food security, China has stepped up efforts on a variety of fronts. One has been to ensure that it has sufficient stockpiles of staple grains. In his 130-page book on food security, Mr Xi barely mentions climate change, but it is a huge problem. The grain harvest in 2024 was helped by the weather: the crop area damaged by natural disasters was unusually low. Last year, however, the president of China Agricultural University, Sun Qixin, said that global warming could reduce China’s yields of wheat by over 6%, maize by over 7% and rice by more than 9%.

Amounts in stock are a closely guarded secret. They could now be at “record levels”, says Gustavo Ferreira of the us Department of Agriculture (usda). But Chinese leaders are not content. They point to “grain rats”: officials who buy low-quality grain for storage, or siphon off supplies and sell them. In December a former minister of agriculture, Tang Renjian, was arrested for bribery, though details have not been made public. “We must always keep tight control of food security—very tight. It is better to produce and store a little more than necessary,” Mr Xi said in 2022, soon after Russia’s invasion of Ukraine.

The Chinese like to point out that their country has 18% of the world’s population but just 7% of the world’s arable land. They now try to ensure that 120m hectares (300m acres) are preserved for farming, mostly for staple crops. This “red line” is close to being breached: in 2023 China had fewer than 129m hectares of arable land, down from 135m hectares a decade before. The new food-security law is partly intended to warn officials that unauthorised use of land could result in criminal sanctions. In recent years farmers in some areas have been pressed to use land where they were growing cash crops for producing grain instead (subsidies have helped, but since land is, in effect, owned by the government, they have little choice). In the past couple of years China has been accelerating efforts to encourage farmers to merge their tiny plots to make it easier to farm more efficiently with machinery.

Officials have their eye on tech, too. While he was minister, Mr Tang called seeds the “computer chips” of agriculture. As with semiconductors, China is putting much effort into producing the best. But Americans control much of the intellectual property for genetically modified (gm) types, which has stiffened the resistance of Chinese officials to allowing their use. Widespread public concerns about food safety have compounded obstacles to gm food production. But it is expanding. In 2023 only 1% of maize-growing land was planted with gm seeds. The usda predicted in 2024 that this could grow to 15% in the next few years.

Chinese leaders used to raise population growth as a reason to fret about food security. That is becoming much less of a concern: last year China’s population fell for a third consecutive year. But since geopolitical turbulence is unlikely to subside, leaders are as nervous and uncertain of the implications of Mr Trump’s second term as many of America’s allies. “The greater the risks and challenges we face, the more we must stabilise agriculture and ensure the safety of grain and key non-staple foods,” Mr Xi said when Mr Trump was last in power. Even beyond Mr Trump, rivalry with the West will continue. Mr Xi will keep thinking about food.