News Chinese hackers target US Treasury computers used for sanctions — Committee on Foreign Investment specifically targeted

I dont understand why Government computers dont have their own internet separated from public ones. and I mean REAL separate one , all the infrastructure cables ... they can wire them along the normal internet cables underground/sea what ever.
 
I dont understand why Government computers dont have their own internet separated from public ones. and I mean REAL separate one , all the infrastructure cables ... they can wire them along the normal internet cables underground/sea what ever.
1. That might have made working from home during pandemic lockdowns a little bit harder.

2. At *some* point, most government systems need to be publicly accessible. I don't know how the process works, but presumably foreign investors need to submit applications/supporting documentation to the CFIUS online. You *could* still have an airgapped private network, where employees retype pertinent information from the public-facing computers to the private ones. But that would cost a lot of extra person-hours (when politicians are always bellyaching about government spending) and introduce human error. Even then, if foreign investors have to divulge sensitive information to the public-facing computers, those will still be an attractive target for hackers, even if they can't get at the private network.