In November last year, when President Donald Trump announced that he had accepted an invitation to visit China in April, the meeting’s agenda appeared straightforward enough. Trade tensions between the world’s two biggest economies were spiralling into a full-blown tariff war, while Taiwan was the lingering flashpoint. Delayed by a month from its original schedule, the upcoming summit, starting Wednesday, now risks being consumed by a more compelling crisis: the war in Iran.

While it is unclear where the West Asia conflict will go from here, even as an uneasy ceasefire continues to hold, two things are now evident: a resolution to the Iran war is ostensibly not that easy, and China’s role will be crucial in whichever direction this conflict is headed.…