Rumor has it that all other armed forces got a similar letter. This particular letter is for the Marines and Navy. Note, the date is October 3, this is something new.
Jade helm was training, done under TRADOC, however, this particular notice authorizes live fire on American soil.
Here is the title: MANPOWER GUIDANCE FOR ACTIVATION AND DEACTIVATION OF RESERVE COMPONENT (RC) MARINES ORDERED TO ACTIVE DUTY ISO DEFENSE SUPPORT OF CIVIL AUTHORITIES
Date Signed: 10/3/2019 | MARADMINS Number: 550/19
Here is a key quote: "Requests for Federal assistance will come with little warning. As required, the Marine Corps must rapidly mobilize RC units and personnel IAW this MARADMIN in order to respond to threats in the Homeland."
What does this mean? It means that civil war in the United States will be answered by America's own armed forces.
However, doing this is risky business, because they will be ordering these soldiers to take action against their own friends and families. This could backfire.
Though the Reserve units have been deployed in the United States for various reasons, having them deploy to "defend civil authorities" is unprecedented, this is something new folks.