

No matter what the protocol is, the chat is completely vulnerable once a single chat member’s phone gets infiltrated. There’s not a set of higher value targets in the world than the US president and his cabinet for actors like China, Russia, Iran, North Korea, and even Israel.
There is a reason national defense related discussion is meant to happen exclusively on a locked-down High-Side network, on exclusively locked-down High-Side equipment that exists exclusively in locked-down High-Side locations.
One story about this for you. MI during the first Trump presidency. There was much said in my office when he tweeted top secret satellite imagery in 2019. My chief went around the shop after this and sat with everybody, and made sure they knew what happened, how this leak got an Intel source burned, how much time/money/effort was wasted from that burned source, how much harder it will be for us to keep the boots-on-ground out there safe, etc.
The tone of the workplace was set after that: “We are here to do our job and keep the guys in the field from getting killed. Our leaders have, and will continue, to make that mission difficult.”