With so much made of Europe's discovery of America, and additional discussion of whether there were pre-Columbian Atlantic crossings, I find myself asking why there wasn't more Asian crossing of the Bering Sea and Strait to explore, conquer, or trade. There were seafaring peoples in northern Asia. What was it about these cultures that made them less inclined to explore or expand? Or is it simply that they did and we don't hear about it or that they did but left little historical record?
Asian cultures did expand into North America. Migrations from Sibera and Alaska were particularly notable. The Thule started colonizing Dorset lands as late as the 1200s:
http://www.jstor.org/stable/25470503?seq=1#page_scan_tab_contents
There are no written records of any of this, so it has to be pieced together through archaeological evidence. No ones even really sure what happened. There's no real evidence of mass violence between the Dorset and Thule, but we do know they didn't interbreed:
http://www.livescience.com/47604-first-american-arctic-people-genetics.html