1. Vietnam is a communist country. 2. Vietnamese government is inherently fear of a color revolution. 3. Vietnamese government just purged its southern pro-West faction to consolidate power. 4. Vietnamese government copies Chinese government every move from opening up to fight corruption. 5. Vietnamese might bitch about China but they love everything about China from movies, dramas, music, culture, and almost everything. 6. Northern Vietnamese are less pro-West and more likely want to maintain peace with China. Given all of these above, I think Vietnam would try to lay low and maintain distance with the US.