The Trung Sisters clearly don't fear retaliation from Champa; their forces are heading north en masse for a bit of Chinese Take-Out.
Clearly second-fiddle, but Burma has some things going for her; cities at 17, 12, 9, 9 and 8; a religion, a wonder (the Colossus is visible in this frame) and most importantly, a lot of mountains between her and the Trungs. A peace with Tibet is basically a formality. Burma may be in good shape to crank out a belated military here and make a move. (Indonesia the most likely target.) ... in general, Burma really needs a decent navy, stat. I like this empire though. Underrated. Soft neighbors to grow fat upon.