Why is the U.S. using Chinese made chips in its Military hardware?

Backdoor Found (Maybe) in Chinese-Made Military Silicon Chips
https://www.schneier.com/blog/archives/2012/05/backdoor_found.html

"Fake microchips from China are causing a growing number of failures in military systems, according to an investigation by BusinessWeek magazine."
https://www.theguardian.com/technology/blog/2008/oct/06/security.china

"For years, everyone has warned that counterfeit microchips made in China and installed on American military hardware could contain viruses or secret backdoors granting the Chinese military cyber access to U.S. weapons systems."
https://www.military.com/defensetech/2012/05/30/smoking-gun-proof-that-military-chips-from-china-are-infected

"For years, the Pentagon has been in overdrive trying to avoid bogus chips from tripping up its ballistic missile protection systems, even worse still, a nightmare scenario of "Trojan horse" circuits from being embedded in parts. But foreign chip-makers — especially those in China — are banging out these chips more and more cheaply, making it harder to track what's getting mixed into military devices."
https://www.wired.com/2011/11/counterfeit-missile-defense/

"The U.S. miltary has known for quite some time that they have a quality control problem with the microchips they've been buying in China."
https://www.theatlantic.com/technology/archive/2011/06/us-military-fake-microchips-china/352255/