Such is the sense of fatigue produced by the back-and-forth battle that has defined the United States-China trade war over the last 18 months that the latest pronouncements on the issue soothed jittery markets but hardly anyone else. President Donald Trump's twin assertions at Monday's close of the G-7 summit that negotiations are about to restart and the prospects of striking a deal are brighter now than ever sounded both familiar and hasty. Yet this is the path that has to be seized, for opportunity lies here. There are good reasons to suspect that the 13th round of trade talks - following the sharp escalation over the last few days as they slapped more tariffs on each other and Mr Trump ordered US companies to prepare to leave China - will not be conclusive.

Notwithstanding the gathering clouds of recession, both Mr Trump and President Xi Jinping may be less than eager to seal a deal in a hurry. Facing re-election in 2020, Mr Trump needs a well-timed deal ahead of the polls in November next year. Struck too early, it may expose him to months of criticism that he could not get enough concessions from China. But if he waits too long, it may upset the economy and sour the voters' mood. China, for its part, may figure that it can afford to wait until after the election to see if it must indeed deal with Mr Trump or a Democrat successor. The more substantive hurdles to a deal have less to do with trade than with strategic rivalry. A deal could be blocked by hawks in the Trump administration pressing an ever harder line on what they see as China's destabilising activities in the Asia-Pacific, pushing for a more proactive policy on Taiwan and keeping a critical eye on the Hong Kong unrest despite China's obvious displeasure over what it sees as foreign meddling in its internal matters. The rise of the hardliners is mirrored in China. Outspoken hawks make the case that the tensions are but a part of a "protracted war" with the US that must be won even at the cost of trade. Their bet is China's one-party political system grants more political and financial levers to Mr Xi than Mr Trump can avail in his highly polarised democracy. Such calculations can only heighten tensions that threaten prosperity.