sitting idle at the fence huh? trust me, Indonesia has done a lot more at international stage (at least in ASEAN itself) since it was proclaimed free, than any other ASEAN countries combined. Funny it comes from you.
Anyway, there's a slight difference between "doing something" and "doing something for someone". We chose to do something, not to do something for someone. It means what we are going to do, should profit us first and if possible profit our partners. Diplomatic doesn't mean helping, diplomatic means saving our own ***.
So please tell me, what can Vietnam offer to Indonesia and the rest of ASEAN countries for standing up against China for you? Can Vietnam replace China as our Exportziel? No, Can Vietnam finance countries like Indonesia and Thailand to patrol the SCS for Vietnam? No, Can Vietnam back Indonesia and Thailand at international forums? No, Can Vietnam offer the necessary technologies to Indonesia and other ASEAN countries? No. So please, what do we get from taking the beatings for you? Your "thank you"? nope we don't need that.