Is the National Guard a militia or not?

Definitely a militia. The vast majority of American National Guard personnel are ordinary people, who usually go to work separately and don't stay in military camps. As long as you spend a certain amount of time (usually 48 weekends) on military training every year, it is a bit like punching in the gym. Only those who are temporarily recruited into the military camp or mission area when they meet the task. Going out to work and taking part in training is paid, which is equivalent to part-time. However, much of the training of the National Guard is with the regular army, with the same equipment as the regular army, and a small number of full-time senior officers and technical arms, such as fighter pilots. Therefore, although the American National Guard is an amateur part-time job in general, it is extremely effective and much stronger than the elite trump cards of many countries.