How do you become an ambassador?

Question

How do you become an ambassador?

Answer 1

In the US, ambassadors are either politically appointed, or are selected from within the ranks of the senior members of the Foreign Service.

Answer 2

Curious is right.  You get promoted from within the Foreign Service or you get appointed politically. It takes a lot of years of stiff competition among very qualified people to advance to the top job. Or it takes a lot of political effort to get a reward like Ambassador. And it takes congressional approval.