“The biggest threat is high-altitude balloons with a small EMP (electromagnetic pulse) nuclear device.”

"Although China has tested balloon-launched hypersonic missiles in the past, that is not a likely use for these blimps," Crespo told The Epoch Times. "The biggest threat is sending one or more of these high-altitude balloons over the U.S. with a small EMP (electromagnetic pulse) nuclear device."

https://militaryview.com/china-can-fire-hypersonic-weapons-and-perform-high-altitude-balloon-emp-attacks/