COMMENT US President Donald Trump’s protectionist threats against China have spurred much concern. If he follows through on his promises and, say, officially labels China a currency manipulator or imposes higher import tariffs, the short-run consequences – including a trade war – could be serious.

But, in the longer term, a turn toward protectionism by the United States could well be a blessing in disguise for China.

There is no doubt that China is going through a difficult phase in its development.

After three decades of double-digit GDP growth – an achievement with few historical parallels – the pace of China’s economic expansion has slowed markedly.

The combination of rising labour costs and weaker demand for Chinese exports has reduced China’s annual GDP growth to 6.9 percent in 2015 and 6.7 percent last year. The Chinese government has now lowered its growth target for 2016-2020 to 6.5-7 percent.

This is still a respectable pace; but it is not the best China can do.

As Justin Yifu Lin and Wing Thye Woo have noted, in 1951, when Japan’s per capita income relative to that of the US was the same as China’s is today, Japan was experiencing sustained growth of 9.2 percent.

One impediment to such growth for China is a heavy debt burden.

A stress-test analysis by the McKinsey Global Institute found that if China continued to pursue its debt- and investment-led growth model, the ratio of non-performing loans (NPLs) could rise from 1.7 percent today (according to official figures) to 15 percent in just two years.

That said, the risk of NPLs is not news to the People’s Bank of China, which will, the evidence suggests, take steps to mitigate it.

Unfortunately, debt isn’t China’s only problem...