The FBI director and the head of Britain’s domestic intelligence agency both raised concerns about the Chinese government on Wednesday, warning business leaders that Beijing is determined to steal their technology for competitive advantage.

FBI Director Christopher Wray reiterated previous concerns by condemning Chinese economic espionage and hacking operations, as well as the Chinese government’s efforts to stifle dissent abroad. His speech was notable, however, because it was delivered at MI5’s London headquarters alongside the agency’s director general, Ken McCallum, in an intended show of Western solidarity.

It also demonstrated how Wray and the FBI regard the Chinese government as more than just a law enforcement and intelligence challenge, but are also aware of the consequences of Beijing’s foreign policy actions.

“We consistently see that the Chinese government poses the greatest long-term threat to our economic and national security,” Wray said. “By ‘our,’ I mean both of our countries, as well as our allies in Europe and elsewhere.”

Officials said it was the first time FBI and MI5 leaders shared a stage for a joint speech.

According to McCallum, the Chinese government’s “covert pressure across the globe” is the “most game-changing challenge we face.”

“This may appear abstract. But it’s real and urgent,” McCallum said. “We need to discuss it. We must take action.” Wray said any forcible takeover of Taipei by Beijing would be “one of the most horrific business disruptions the world has ever seen,” referring to current tensions between China and Taiwan.

Last week, the director of national intelligence for the United States said there were no signs that Chinese President Xi Jinping was planning to invade Taiwan militarily. According to Avril Haines, Xi appeared to be planning for that potential action as part of a larger goal of Taiwan reunification.

Following his meeting with his British counterpart, Wray stated that he would leave it to others to determine whether an invasion of Taiwan was more or less likely in light of Russia’s invasion of neighboring Ukraine. “I don’t have any reason to think their interest in Taiwan has abated in any fashion,” Wray said, adding that he hoped China had learned what happens “when you overplay your hand,” as he said the Russians have done in Ukraine.

The FBI director stated that there are signs that the Chinese have looked for ways to “insulate their economy” against potential sanctions, possibly drawing lessons from Russia’s experience since the war.

“In our world, we call that behavior a clue,” said Wray, who urged caution from Western companies looking to do business in or with China throughout his speech. He warned that if Taiwan is invaded, Western investments in China could be lost.

“Like in Russia, Western investments built over time may become hostages, capital stranded, and supply chains and relationships disrupted,” he said.

President Joe Biden stated in May that if China invaded Taiwan, the US would respond militarily, making it one of the most forceful White House statements in support of Taiwan’s self-government in decades. The White House later attempted to downplay the significance of Biden’s remarks, claiming that he was not outlining a shift in US policy toward Taiwan, a self-governing island that China regards as a breakaway province that should be reunified with the mainland.