"Gaslighting", that's called.
Make the object of your affections begin to doubt what is real, or otherwise. It's hard to do well, but from a single person up to an entire army, it IS possible...
(Think of all the fake radio traffic in the first Gulf War, making Saddam think they were coming in through Kuwait, while everything with move was doing the "Hail Mary Pass" movement...)
I'd have Ansom looking at his own people as traitors by the time he gets to GK...
PsyOps are fun.