Jingo

n. pl. Jingoes (#).
  1. A word used as a jocular oath.
  2. A statesman who pursues, or who favors, aggressive, domineering policy in foreign affairs; a bellicose superpatriot or chavinist.

This sense arose from a doggerel song which was popular during the Turco-Russian war of 1877 and 1878. The first two lines were as follows: -- 1913 Webster We don't want to fight, but by Jingo if we do, We 've got the ships, we 've got the men, we 've got the money too.