The Globe and Mail reports in its Wednesday edition that there is not much doubt about why Prime Minister Mark Carney is going to China. The Globe's Campbell Clark writes that U.S. President Donald Trump's tariffs mean this country needs to diversify its trade. China could buy more Canadian meat, seafood, oilseeds, oil or natural gas. The possibilities are vast. So Mr. Carney is off to Beijing, to rebuild relations that turned bitter in 2018, when Canada arrested a Huawei executive at the request of the U.S. and China responded by throwing two Canadians in jail. A deal on Chinese EVs would bring groans from Ontario's carmakers and the U.S., but the problem with any such deal is it is unreliable because of the nature of the partner. In a year or two, China might find a new reason to bar canola products. Mr. Carney seems to see the problem. Still, there will be a political temptation to make concessions to China for the reward of short-term trade benefits. The value of a reset with China will be limited if it is the same-old promise. China is not afraid to punish smaller trade partners such as Canada because there is always another willing to do business, and that requires co-ordinated strategy with other countries.