After leaving Arnold on his grandparent's doorstep, his parents went to Myanmar(the endpoint of Arnold's map) and constructed a space-faring vessel capable of faster-than-light speeds and sustaining human life aboard it for up to one hundred and twenty years.
In a twist much like the pilot of Thundercats, his parents crashed on a faraway alien planet twelve years after taking off, and the cryostasis pods in which they slept malfunctioned and released them from their slumber.
After an brief exploration, the adventurers discovered the planet was not only able to sustain human life, but it was inhabited by two rivaling species locked in a brutal and unending war: the anarchic, liberalist Dubaku, and the zealous, totalitarian K'Gosi.
Arnold's parents joined the Dubaku military, and they've been battling the K'Gosi ever since.