France, July 5 -- China's top diplomat Wang Yi's high-profile tour of Europe this week has been dominated by deepening trade tensions and mounting security concerns, with relations between Beijing and the European Union their most strained in years. Meanwhile, Brussels is attempting to maintain good relations with Washington, in the face of President Donald Trump's unpredictable policies.

While Wang is touring Europe and meeting with top decision makers, China's commerce ministry moved to massively increase some tariffs on EU products.

The Chinese ministry, which announced the measure on Friday, said its investigations had found that EU brandy was being dumped on the Chinese market, threatening domestic producers. The country's anti-dum...