Jack Ma, founder and executive chairman of Chinese e-commerce giant Alibaba, warned against President Donald Trump’s threatened trade war with China.

“It’s easy to launch a war, but it’s so difficult to stop a war,” Ma said on stage at the Fortune Global Forum business conference in Guangzhou, China on Tuesday.

Ma, whose company is pushing to become a global powerhouse, including in the United States, would, of course, be a big loser if the Trump Administration clamped down on China over what Trump describes as that country’s unfair trade practices. Imposing extra tariffs on Chinese imports would make goods sold through Alibaba’s web sites—which include rivals to eBay and Amazon—more expensive to U.S. customers.

Habitually optimistic, Ma avoided criticizing Trump, who he met at Trump Tower in January during the presidential transition and then gushed about in front of cameras downstairs as being “smart” and “open minded.” Instead, Ma minimized any differences between the two countries, saying “even a wife and husband have problems” while preaching the virtues of globalization.

“We have to make sure that every country benefits from globalization,” he said. “We have to make sure that farmers can sell things, we have to make sure that young people benefit.”

Alibaba, Ma argues, helps small U.S. businesses by giving them a huge international market for their products and a cheap source of supplies. And that translates into more U.S. jobs, something that is music to President Trump’s ears—at least when he’s not bashing China.

“He’s making progress,” Ma said of President Trump. “He’s trying hard.”

Ma’s advice is for business leaders to take the initiative when it comes to trade policy, no matter which way the wind is blowing in Washington or Beijing.

“We should never wait for policies,” Ma said. “We should go before the policy and try to do it.”

That simple strategy sounds convincing coming from Ma, a master salesman who transformed the startup he founded 18 years ago into an online powerhouse with market value of $433 billion. But reality can be a lot tougher when it comes to international trade diplomacy, especially with a president who campaigned on “America first” and unilaterally canceling trade deals.