While reporters and pundit made countless Pink Floyd references after China's Change'e 4 probe landed on the far side of the moon Thursday, a leading expert on China says this achievement is part of a very ambitious military buildup that represents the greatest threat to U.S. national security.

"China is the number one threat, the number two threat, the number three threat," said China expert Gordon Chang, author of "The Coming Collapse of China."

Chang says China wants to do a lot more than just go to the moon.

"This is important.  China has ambitions to mine minerals and the rest of it, but they're also going to use the moon for military purposes," said Chang.  "Remember the Chinese space program is not civilian.  It's all military, dominated by flag officers.  Everything they do has a military implication."

One area of concern is the security of U.S. satellites.  Right now, the satellites in high earth orbit can be tapped into by our rivals, but that could change it China can take action from the moon.

Chang is disheartened that the U.S. is pulling back from space by grounding our shuttles, relying on other nations to get our astronauts to space, and scrapping plans to return to the moon and eventually get to Mars.

He is hopeful that President Trump's creation of a Space Force will reignite the push to be the dominant player away from the earth as well.

"Space is absolutely critical for success on the battlefield and we're going to have to be able to dominate space," he said.

Listen to the full podcast to hear Chang further explain why he believes China is far and away the greatest threat to national security and why China has some serious vulnerabilities that the U.S. may be able to exploit.