First, getting the US, China, and Russia to work in unison seems like a tough feat.
And even if they did control the majority of STATIC nodes, they wouldnt control the network.
From the FAQs...
While owning 51% of the STATIC nodes would not be technically or financially impossible, this in itself does not ensure control over the STATIC node network. With PoSign consensus, a minority of STATIC nodes or even a single offline STATIC (call it an ace in the hole) could blacklist any number of STATIC nodes that do not agree on consensus.
In this case, owners of the blacklisted STATIC nodes would have to come back into consensus before they would be allowed to return to active status.
Simply put, a 51% attack is not a possibility on the XTRABYTES network.
https://community.xtrabytes.global/faq/why-isnt-xtrabytes-vulnerable-to-a-51-attack.95/Thank you; it seems to me for safety the static nodes should preferably be distributed throughout the globe so as not to be too geographically dependent. Also, they should be as anonymous as possible (so as to be under the radar); Not sure is this is achievable under XBY since I believe nodes are known and identified . Anyhow, that was just a thought, not that I want something like that to happen, as a XBY investor!