In civilian life they are plumbers, bankers, doctors or farmers. Now, thousands of US National Guard reservists are on the front lines of the capital, tasked with keeping the peace during President-elect Joe Biden's inauguration next week.
While President Donald Trump's most fervent supporters still refuse to acknowledge his defeat in last November's election, more than 21,000 National Guard troops have begun pouring in from across the country to prevent a repeat of the deadly assault on the US Capitol last week.
They "will conduct security, communications and logistical support operations" to protect the ceremony, according to the National Guard office.
In a sign of how exceptional the situation is, the reservists will be armed. They will only be permitted to carry out arrests "as a last resort," according to the Pentagon.
US service members do not have the right to search, seize or arrest civilians, under the "Posse Comitatus Act", an old law originally intended to prevent the use of the US military against US citizens.
But reservists have sometimes been allowed to carry weapons, such as during the movement to protest racism and police brutality after the death of George Floyd, an African-American man suffocated by a white policeman in May last year in Minneapolis.
The absence of the National Guard during the assault on Capitol Hill by pro-Trump protesters on January 6 has been criticized, but officials stressed that their presence was not requested in advance, and that this particular branch of the US Army, which includes 335,000 reservists, was never intended to be a rapid reaction force.
That is because before they can actually get to the place they are being deployed, reservists must first leave their work, return home to recover their uniform and pack their bags and go to the armory of their state, which is sometimes several hours drive from their home, to equip themselves.
They must then get to the designated site of operations, often by plane. Hence the daily arrival in Washington of new units before the investiture on January 20, and their increasingly visible presence.
More than 2,000 reservists are also to be deployed in some states where Trump supporters could stage violent demonstrations, such as Wisconsin or Pennsylvania.
At the same time, more than 21,000 National Guard soldiers continue to participate in the fight against the COVID-19 pandemic. Reservist nurses and doctors are bolstering the swamped emergency services, while others are contributing to the mass vaccination roll-out.
In addition, some 2,500 National Guard reservists were still deployed in September 2020 in theaters of war, according to the latest Pentagon figures.