China must change its ways or it risks plunging the world into a new depression, European Central Bank President Christine Lagarde said — ever so diplomatically — in a rare visit to Beijing on Wednesday.

In a speech to the People’s Bank of China that drew heavily on the trade-induced economic crises of the 20th century, Lagarde stressed that China and the U.S. had to share the burden of closing the massive trade gap that threatens to tear the world economy apart.

“If we are serious about preserving our prosperity, we must pursue cooperative solutions — even in the face of geopolitical differences. And that means both surplus and deficit countries must take responsibility and play their part,” she said. 

Lagarde told her audience that the U.S. and Europe will not allow China to destroy vital industries with what increasingly appears to be a conscious policy of flooding the world with its own goods.

“Given national security considerations and the experience during the pandemic, a certain degree of de-risking is here to stay,” she said. “Few countries are willing to remain dependent on others for strategic industries,” especially when they perceive the other’s trade policy as unfair.

Lagarde’s visit comes at a critical time for the world economy, as U.S. President Donald Trump tries to reset the global trading order with a suite of punitive tariffs on the U.S.’s largest trading partners. American officials have spent the last two days in talks in London with their Chinese counterparts, trying to break a deadlock in which both sides accuse the other of withholding goods vital to their economies.

With a nod to the tariff wars that ushered in the Great Depression, Lagarde warned that “coercive” trade policies would make things worse for everyone. She also noted that in the crises of the postwar era, the U.S. and its trading partners at least had a shared geopolitical imperative — to win the Cold War — that incentivized them to patch up their quarrels.

By contrast, she implied, the U.S. has no such constraints vis-à-vis China today. That only makes the situation more dangerous for the world economy, she noted, since trade and international supply chains now play a much larger role than in the past.

As trade-related tensions have boiled over, financial markets have speculated on the idea that the U.S. dollar’s dominance in global finance may be weakening, and that the euro may accordingly develop a greater role as a reserve currency.

However, Lagarde, who has enthusiastically bought into that notion, made no mention of such issues in her speech on Wednesday. An ECB spokesman declined to elaborate on the topic of any private exchanges she had scheduled with Chinese officials.