It depends on the person. My uncle, Walter Ratliff, was in the Air Force 25 years before his appointment. If you search his name there is a good biography about his career online. The position is permanent and nominated through a process involving congress, the senate, secretary of defense and passes the presidents desk before the position is confirmed.
15 yrs including police or time in the army
5 years
Gary Paulsen's father served in the army for about 20 years.
I think he served 2 years in the Army
He served 4 years in the Military in WWI.
2000 years,anyways when a new city/town is created army is with them all the time.
1985-1987 Total time in army 10 years 2 months
A standard term of enlistment in the US Army in 1964 was 2 years. Source: My dad, who was enlisted for 2 years.
About 40 years
one
it took 15 years to build the terracotta army
"How many years does it take to become a chemotherapist?"