So you want to cut off Pearl Harbor from the rest of the USA before you attack it? Too easy.

Ninety percent of communications traffic, including diplomatic and military, into and out of Hawaii is carried by just 17 undersea internet cables. More importantly, they are collected into just a few offshore 'nodes' from where larger cables carry their signals to the islands.

Russia has been busy mapping undersea cable locations. It goes without saying that China has too.

https://www.theguardian.com/uk-news/2022/jan/08/uk-military-chief-warns-of-russian-threat-to-vital-undersea-cable

So, the USA's main adversaries know exactly where the cable nodes are. China can't do much with that knowledge, right? Wrong.

Meet China's new and very potent submarine force. First, the Shang class nuclear attack sub. China possesses six Shang-class nuclear powered attack submarines (SSNs). These submarines are 110 meters long with a 11-meter-wide beam and can travel up to 30 knots when submerged, range ... unlimited. Their weapons systems include cruise missiles but to destroy a cable node they only need a torpedo ... hell you can even do it by dropping an anchor on top of it.

Or then there is this bad boy. The HSU 001. An unmanned submersible that can be dropped off a mothership and navigate itself to any point on the globe. Fill it with high explosive and set it to detonate over an undersea cable node? No problem. Want a doomsday scenario? How about this. Put a nuke on it and park it off the Hawaii coast.

Ah, but that still leaves a communication capacity of about ten percent via satellite, right? The US military could just commandeer bandwidth on military or commercial satellite systems to make up for the loss of cable bandwidth. Yes, though nowhere near the bandwidth needed to manage a high intensity conflict. And NO. Welcome to China's not so secret weapon: the anti-satellite satellite. As long ago as 2013 China launched small maneuvering satellites capable of intercepting other satellites in orbit, some with robot arms for 'interacting with them' (read, shoving them out of orbit.)

In 2018 Lt. Gen. Jay Raymond, commander of the 14th Air Force, said that China is amassing formidable anti-satellite capabilities. Raymond claimed that Beijing is already capable of holding every low-orbit satellite at risk, and “soon every satellite in every orbit will be able to be held at risk” by China’s anti-satellite (ASAT) capabilities.

So, a torpedo here, and HSU there, an anti-satellite satellite there, and Hawaii is cut off from the world, unable to call for help except by ... say, long wave radio.

Which, oh yeah, can easily be jammed. Dang.