said by longstreet :

Hmm, interesting.

I would say any country that ties their critical systems to the Internet so foreign powers can touch them is foolish.

I highly doubt either China (they are the enemy? - ok) or the United States has such systems exposed.

The infrastructure the U.S. military uses to both launch and defend against cyberattacks runs through the public Internet system. Military networks such as the Global Information Grid are linked to U.S. government and critical national infrastructure systems, which in turn are linked to the public Internet. Adversary systems are subverted by the U.S. military through public channels--however, this also leaves the U.S. military open to attack through the same channels, said Elder.

"The infrastructure on which the Air Force depends is controlled by both military and commercial entities and is vulnerable to attacks and manipulation," Elder said.

said by longstreet :

To attack the public internet, you have to be on the public internet.

My point is :

[Critical] systems are NOT on the public internet

said by Mchart :

I'd consider DISN to be critical.