Career and job required basic training in martial art and boxing.
All military personnels from soldiers to generals required training in
martial art. Admission requirment for military academy in every
country
is different.

Quotation from wikipedia:
http://en.wikipedia.org/wiki/United_States_Marine_Corps_rank_insignia
http://zh.wikipedia.org/wiki/%%E7%%BE%%8E%%E5%%9B%%BD%%E6%%B5%%B7%%E5%%86%%9B%%E...

Commissioned Officers
See also: United States Marine Corps officer rank insignia
Commissioned Officers are distinguished from other officers by their
commission, which is the formal written authority, issued in the name
of the President of the United States, that confers the rank and
authority of a Marine Officer. Commissioned officers carry the
"special trust and confidence" of the President of the United States.
[1] Commissioned officer ranks are further subdivided into Generals,
field-grade officers, and company-grade officers.