You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
alternatehistory.com
The expansion of Vietnam throughout most of its history could be described as "Champa-screw" (with a little bit of Cambodia-screw for the Mekong Delta) as the former expanded its territory southward through conflicts and/or treaties with its (former) Indianized Austronesian neighbor.
I was really thinking recently of an alternate Vietnam that expanded westward to the east bank of the Mekong River instead of expanding south; what POD should be needed to realized it?
What would be the possible impact on the following:
1. Tai migration to present-day Thai territory, especially in the Isan region.
2. The settlement of the northern tip of Sumatra.
3. The effects of a surviving Champa on the history of (continental) Southeast Asia.
4. Impact on the other Austroasiatic groups living in OTL Laos.