Back in the days of the Rainbow series, the Orange Book required that data that was marked as secure could not be transferred to any location or user who was (a) not authorised to access it or (b) did not have the security permissions regardless of any other authorisation. There was an additional protocol, though, listed in those manuals - I don't know if it was ever applied though - which stated that data could not be transferred to any device or any network that did not enforce the same security rules or was not authorised to access that data.
Regardless, in more modern times, these protocols were all abolished.
Had they not been, and had all protocols been put in place and enforced, then you could install all the unsecured connections and unsecured servers you liked, without limit. It wouldn't have made the slightest difference to actual security, because the full set of protocols would have required the system as a whole to not place sensitive data on such systems.
After the Clinton email server scandal, the Manning leaks, and the Snowden leaks, I'm astonished this wasn't done. I am dubious the Clinton scandal was actually anything like as bad as the claimants said, but it doesn't really matter. If these protocols were all in place, then it would be absolutely impossible for secure data to be transferred to unsecured devices, and absolutely impossible for secure data to be copied to machines that had no "need to know", regardless of any passwords obtained and any clearance obtained.
If people are using unsecured phones, unsecured protocols, unsecured satellite links, etc, it is not because we don't know how to enforce good policy, the documents on how to do this are old and could do with being updated but do in fact exist, as does the software that is capable of enforcing those rules. It is because a choice has been made, by some idiot or other, to consider the risks and consequences perfectly reasonable costs of doing business with companies like Microsoft, because companies like Microsoft simply aren't capable of producing systems that can achieve that kind of level of security and everyone knows it.