Okay, I have a theory.
Charlie may or may not have ordered Sammy to capture or croak Ansom; however, it seems obvious to me that Jillian thinks this may be the case.
Now, assuming this is the case, Jillian will likely take some kind of action. She may think she has no choice but to break alliance in order to protect the man she loves (Ansom) from people whom she believes are hellbent on eliminating him.
That being said, I think we may have seen that the strain we saw on Charlie earlier may have led him to make a tactical misstep. Let's say, for example, that he's given Sammy the following orders:
"Kill half of the enemy's pikers and as many heavies and cavalry as you can; if you can kill half the pikers and all of the heavies/cavalry before you lose half of your troops, you can pull back. Otherwise, keep fighting until you've lost half your troops, then withdraw. Oh, and if you tell anyone of these objectives, our deal is null and void."
However, since he can't tell anyone what his objectives are - and Jillian doesn't know what they are - both she and Tramennis may have assumed that Sammy's been ordered to croak Ansom if he can, or do as much damage as possible before he loses half his troops if he can't reach Ansom.
Jillian doesn't want to lose Ansom again, so she might believe she'll have to break alliance to protect him.
The strength of our future lies in our past.
There is no instance of a nation benefiting from prolonged warfare.
-Sun-tzu, The Art of War