The relationship between the US and China is the most consequential of the 21st century. Conflict between the two great powers is not inevitable. The world has changed since Thucydides described the collision between Athens and Sparta in the Peloponnesian wars. The risks, however, are high. Competition is unavoidable; misunderstandings and miscalculations likely.

After a period in which US presidents sought to co-opt Beijing into the existing order, Donald Trump has set a path of unilateral confrontation. The about-turn has struck a chord beyond the economic nationalists and China hawks who count themselves among Mr Trump’s natural supporters. The global ambition of President Xi Jinping’s “ China Dream”, frustration with Beijing’s unfair trade and investment policies, and the plundering of the west’s intellectual property have fed wider disenchantment.

The shift in US policy started before Mr Trump’s presidency. Barack Obama’s “pivot to Asia” in 2011 heralded a more robust military posture balanced by a Trans-Pacific Partnership incorporating US economic interests. Washington’s invitation to Beijing to become a “responsible stakeholder” in a US-designed global order had run its course.