The shootout has come to represent Change_sentiment a period of the American Old West when the frontier was virtually an open range for outlaws , largely unopposed by law enforcement officers who were spread thin over vast territories .

Starting Process_start from Emperor Wu 's reign ( r. 141–87 BC ) , the Han empire changed Change from a relatively passive foreign policy to an offensive strategy to deal Resolve_problem with the increasing Xiongnu incursions on the northern frontier and also according to general imperial policy to expand Expansion the domain .

Pagan did contest Competition but its army was driven Motion back at the frontier by the Mongol Army in 1277–78 .