Soldiers need to be able to communicate on a noisy, dangerous battlefield even when conventional means of communication are unavailable.
To help meet that need, the US Army has just updated its compilation of hand and flag signals.
One configuration of flags signifies “Chemical, biological, radiological, and nuclear hazard present”:

Or a soldier may need to signal “I do not understand,” as follows:

See Visual Signals for Armor Fighting Vehicles (Combined Arms), GTA 17-02-019, US Army, February 2018.
Satellite imagery of RAF Lakenheath reveals new construction of a security perimeter around ten protective aircraft shelters in the designated nuclear area, the latest measure in a series of upgrades as the base prepares for the ability to store U.S. nuclear weapons.
It will take consistent leadership and action to navigate the complex dangers in the region and to avoid what many analysts considered to be an increasingly possible outcome, a nuclear conflict in East Asia.
Getting into a shutdown is the easy part, getting out is much harder. Both sides will be looking to pin responsibility on each other, and the court of public opinion will have a major role to play as to who has the most leverage for getting us out.
How the United States responds to China’s nuclear buildup will shape the global nuclear balance for the rest of the century.