The National Guard said it had deployed 12,000 additional Air and Army Guardsmen for civil-unrest response in 23 states and Washington, D.C., making the 67,000 members now on the streets for the protests and Covid-19 the largest number ever activated in the U.S.

The National Guard expanded its civil-unrest presence from roughly 5,000 to 17,000 from Sunday to Monday following clashes over the weekend, reaching a total that surpassed the 51,000 activated during the 2005 Hurricane Katrina response.

The new troops were in response to protests that had spread across the country following the death of George Floyd, said Wayne V. Hall, a spokesman for the National Guard Bureau.

The National Guard works with local law enforcement. While each mission varies by state, troops can be used for civil-disturbance control, as site and personnel security, and for critical infrastructure protection, among other duties. They can use Tasers, pepper spray and batons, according to a release from the National Guard.

“In all cases, state and local law-enforcement agencies remain responsible for security. The National Guard will respond to their requests for assistance in augmenting law enforcement,” said Mr. Hall.

Read More