Strike One's Flag Meaning

(idiomatic, by extension) To yield, give up, or surrender.

Example: 1850, Herman Melville, White Jacket, ch. 74:
  At length, having lost her fore and main-top-masts, and her mizzen-mast having been shot away to the deck, . . . the English frigate was reduced to the last extremity. Captain Cardan ordered his signal quarter-master to strike the flag.
1864 Feb. 7, "Very Latest Per Edinburgh," New York Times (retrieved 2 July 2015):
  An Austro-Prussian army of 120.000 men . . . is of itself so imposing a spectacle that one is tempted to believe the little Kingdom of Denmark will strike its flag without firing a shot.
1921, Jeffery Farnol, Martin Conisby's Vengeance, ch. 12:
  The enemy having yielded to our mercy and struck their flag, we ceased our fire, and thinking the worst over and done, I watched where Belvedere conned the ship with voice and gesture.
2014, David Berreby, "What If We Start Talking About Race Like We Talk About Religion?," bigthink.com (retrieved 2 July 2015):
  The point of this exercise wouldn't be to cause one side of the argument to see that the other is correct and strike their flag.