"The spy balloon incident is a reminder to most and a wake-up call to some in terms of how serious China is as an adversary in seeking regional and global domination," the retired general said.
The U.S. shot down an alleged Chinese spy balloon two weeks ago off the coast of South Carolina that had been flying across the U.S. for several days.
Keane said that China’s threat is further increased due to the country's "rapid military growth" and "exploding" nuclear program.
U.S. forces haul debris from China's surveillance balloon onto a boat off the coast of South Carolina. (US Fleet Forces)
"We’ve got to make certain that we have a military deterrent to deal with that threat, that I believe has eroded significantly," he said.
CHINA'S TOP DIPLOMAT CALLS US RESPONSE TO BALLOON INCIDENT ‘HYSTERICAL’
Keane said he believes the ncident can be used as a "catalyst" to "galvanize" the U.S. against such threats.
"We don’t shoot down a surveillance balloon when the mission is complete, we shoot it down before it starts," Keane said. "That has got to be the lesson learned."