China may already be sharing data with Russia, and America wouldn’t stand “a fighting chance” if the two superpowers combined their cyberwarfare capabilities, the U.S. Air Force’s former chief software officer told Fox News.

“Not many nations would be able to push back,” Nicolas Chaillan told Fox News. “I don’t even think the United States would be able to push back if tomorrow Russia and China decide to come together against us.”

“I think it would be very difficult for us to be able to even have a fighting chance, let alone a nation like Ukraine,” he added.

Russia entered its eighth day of fighting after invading Ukraine on Feb. 24. Western intelligence predicted the superpower would quickly sweep through its neighbor, but Ukraine still controls its capital, Kyiv.

Chaillan said “this is not the full force of the Russian capabilities,” which he called “tremendous.”

“They have not used the most innovative capabilities yet,” Chaillan told Fox News. “They’re focusing on the more traditional warfighting capabilities.”

“We have to be cautious. I always remind people that [Russian] President [Vladimir] Putin is not stupid,” Chaillan said. “We may not yet understand what his plan was all along.”

But the former Pentagon official said he’s “way more scared about China.” Chaillan said it would be “game changing” if China provided Russia with advanced technologies.

Chaillan believes China would first give Russia cyber offense capabilities.

“You also have some AI and machine learning capabilities that could be used to look at satellite imagery and find where troops are located, be able to do better real-time analysis of what’s going on on the ground,” Chaillan said.

The former Pentagon official said he wouldn’t be surprised if China was already sharing data with Russia. But he warned of possible repercussions if the U.S. or other Western nations offered the same support to Ukraine.

“We have to be very careful,” Chaillan told Fox News. “If we start providing cyber offensive capabilities, nothing stops Russia from fighting back and going after our critical infrastructure.”

The International Institute for Strategic Studies placed the U.S. as the lone country in its top tier when assessing 15 nations’ cyber power. China and Russia were ranked in the second tier, along with Western countries like France and the United Kingdom.

But Chaillan said the cyber defense for critical infrastructure, like power and water systems, is “at the kindergarten level.”

“It would be very impactful to U.S. citizens if something were to happen,” Chaillan said. “They could potentially take down the grid for weeks, if not months.”