Some government leaders, like the president, have the power to other people to positions of power.

appoint, promote

Explanation:

any synonym could work

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.

united states reinforcements contributed greatly to three allied victories in france at: cantigny (first major american battle), argonne (the largest in the united states military history, involving 1.2 million american soldiers), and château-thierry (one of the first actions under general pershing).