My friend, the Philippines is a vast archipelago of 7100 islands, with rugged terrain, making it a perfect area for constant guerilla warfare, in fact, this was the case with Japan when my country and your country went to war many many years ago, the Filipino Scouts were deadly in ambush warfare, and was a constant threat for the Imperial Army. Due to the terrain of the Philippines , tank warfare is not practical unless one gains beachhead and establishes a command and control zone; any PLA -related strike would meet stiff resistance from the PA if they were equipped with the JGSDF's Type 01 LMAT.
In fact, I believe the Philippine Army should equip every single battalion with at least 2 squads specifically dedicated int anti-tank warfare. What's amazing about the Type 01 LMAT is that it is adaptable; it can be used for anti-tank, anti-artillery purposes, but can also be used for anti-infantry purposes.
And they're deadly accurate, too. Imagine the outcome!
There is only one country that has been vocal in ASEAN and has gone against the majority, even arguably played as a 5th column. And that is Cambodia.
However, I'm sure and quite confident that the Vietnamese will be more than willing (and able) to keep an influence in Cambodia.
Any problem has a solution, my friend.