The Dutch started by launching small incursions and skirmishes against the Portuguese. The militarized frontier would serve as a buffer against Ottoman incursions. The effectiveness of this control is emphasized by regular military incursions and rocket attacks. Incursions of American reconnaissance aircraft from nearby Alaska sometimes happened. About 1,500 British troops remained in Belize to deter any possible incursions. Since the armistice, there have been numerous incursions and acts of aggression by North Korea. These border incursions continued into Sargon's reign. They were predominantly refugees from the incursions of the Lombards. The country descended into political chaos, with frequent Ottoman and Tatar incursions and pillages. They banded with the Maricopa for protection against incursions by the Yuma and Apache tribes. The Dacian theory could also be consistent with the known patterns of barbarian incursions. Jephthah became the leader in resisting these incursions. Electric fences have also proven successful as a means to secure perimeters from bear incursions. The gods also needed to stop the organized mortal incursions into their planes. The Portuguese Empire therefore became an appropriate target for Dutch military incursions.