The trade conflict heating up between China and the United States can be dangerous and could lead the two nations to slip into a "Thucydides Trap", Harvard professor Graham Allison said in an interview with China Daily on Tuesday.

To avoid the trap — the notion that a conflict could develop when a rising power challenges an established one — the two nations should first recognize how dangerous the outcome might be and then find a new form of great-power relations to avoid it.

A tariff war between the world’s two largest economies could do serious damage to both, he said.

But economic damage from a trade war is not the most significant risk, he said.

He notes that in the past 500 years, there have been 16 cases in which a rising power threatened to topple a ruling power from its predominant position. Twelve of those cases led to war.

Speaking on China-US trade conflict, Allison said, "...Even worse than the economic impact would be if it should become part of the fuel that produces fire."

Over the past four decades, the US viewed China as a "partner" or "strategic partner", he said. But the Trump administration now publicly call China a "strategic rival" or "adversary", which shows a fundamental shift in the way Washington thinks about China and how the US should relate to it.

"That (shift) in this Thucydides dynamic, makes it even more dangerous," he said. "In this dynamic, we should ask the question President Xi asked, which is how to escape the ’Thucydides’s Trap’, that’s the right question to ask."

"The first step to escaping the ’Thucydides Trap’ is to recognize the trap and how dangerous it is if we slip into the trap," he suggested. "Then secondly is how can we find a way to escape the trap; President Xi’s idea is we should have a new form of great-power relations, I think this is a great idea."

"Now we have to construct all the elements of the new form," Allison said, indicating that the process would require the two nations to cooperate.