The best thing both of them can do (and every other tech giant that is not Chinese) is to put up a moat around China and contain all the competing Chinese tech

The best thing both of them can do (and every other tech giant that is not Chinese) is to put up a moat around China and contain all the competing Chinese tech companies to only China. This means putting extra effort into every country that borders China and every country with whom China has a strong economic relationship. This isn't too different to how Facebook conquered universities where it was #2 to some other social network. Instead of trying to replace the social network at that university (A) with Facebook, it focused on all the universities (B, C, D, etc.) around that university (A) so that there would be a strong social network composed of the secondary universities (B, C, D, etc.) and that would lead students at the first university (A) to join Facebook when they made friends with students at the secondary universities (B, C, D, etc.).