US has had some sort of troops deployed for some period in Taiwan in the past as well.I thought having hostile foreign troops stationed on Chinese land was one of the triggers for armed reunification? You're also thinking too small, our enemies are ontologically evil; no act against them is wrong.
The change here is that they are going to be "permanent" now.
In any case, China isn't the only country in the world that can salami slice. The US can do it too. However, I would say that Chinese salami-slice is far bigger and more meaningful than US salami-slice