I mean, even disputes and war could only explain part of the story (U.S. is also in war with Vietnam, so as Japan and many others). I suspect their(Vietnam government's) altitude towards the Internet maybe also played a role in there.

As far as I know, Vietnam's Internet giants is far smaller compare those in China and U.S. So even if Vietnam going to full-boom in 5G (That currently require equipments from Huawei to keep up to the speed), that will still be more beneficial to international companies than domestic ones.

Maybe that's another reason why they're willing to claim down and making decision with such leverage.