If I had to guess if there were a strategic reason it’s that unfortunately for counties like China/Vietnam late to the party their electronic warfare and hacking capabilities are underdeveloped and years behind those of the west that was first to the game. I don’t like it but there are allegedly rather mercenary isn’treali companies like those that provide iPhone hacking tools that sell to China and Vietnam and allow them to have tools they might not otherwise have of use for counter-espionage, police-work, and perhaps even as a basis for building out state campaigns to strike back at the aggressive west.

For the zionist regime it’s not like the US can necessarily stop them from doing this (though they’ve kind of been trying lately) so playing both sides means they make a bit of extra money and further insulate themselves against being isolated. And like it or hate it and I do hate it, without the west joining any campaign to isolate them Vietnam/China taking a principled stance against the zionist regime isn’t going to do shit. They will only fall when the west’s support is pulled or when the west itself is too weak to matter but that is still something decades away.