While China definitely has the finances to back up causing any trouble I'm not so certain that they will be able to divide the ASEAN nations as we assume. While there are some big differences between the nations one thing they all have in common (excluding Laos, Cambodia, Thailand and to some extent Burma) is that China has used there muscle to try and bully them into doing what China want's.
Hard if not impossible to cause division when you have turned all parties involved against you and those not against you have no stake and are of no use in the dispute.
As it is while beyond Singapore we may not share any true deep allied relations we do share historical ties with some and common interests with others.
Individually any single nation excluding the US would have no chance against Russia, But when you consider that they have pi**ed of South Korea, Japan, (Taiwan?), Philippines, Vietnam, Brunei, Malaysia, Singapore, Indonesia? and Australia? and they actually do start to have them selves spread thin some what.
Even the most opposite of nations can put aside there differences to stand up to a common enemy (USA/USSR vs Nazi Germany).
That all being said there is no guarantee with Trump, He back flips so often he would likely announce war against some nation just to say they are really great guys the day after
