Longtime lurker first time answer-er but I did read the rules.

First I would say I don't know that ancient warfare and politics are exactly analogous to today, so this question is a bit vague and problematic. There were a great many assassinations that were partially or completely obfuscated from the populace. Additionally many important parts of the war machine were proprietary. Scandals, cults of personality all that sort of thing happened very frequently.

The best example I can think of for what you are looking in more of a state sanctioned deception for is how Caracalla started his Parthinian Campaign. There are differing accounts which is what makes the story more sensational. I would recommend checking out Herodian's and Cassius Dio's accounts of Caracalla's Parthian Campaign (Or the Battle of Nisibus). It is basically the historical inspiration for ASOIF's red wedding, or so I am told I don't watch the show. I was able to find a good translation of Herodian but not Cassius Dio, I am sure you could with a little work. http://www.livius.org/he-hg/herodian/hre411.html. Herodian's also includes more detail about Caracalla's assassination after the battle which is interesting as well. Cassius Dio spins (or just kinda ignores) Caracalla's treachery so he comes out much more favorably. That is the account that would have been presented to the Roman subjects. How many of them knew better, where, and in what time frame I don't know. That is more of a anthropology question I would say.

Edit:

4.10-5 is the main section. I don't know if I have to state my background but I have a BA (finishing minor and graduating this fall) in History from UMD and I took a few classes on warfare in the middle east/ancient warfare that sort of thing. Certainly not an expert which is why I leaned on the primary and didn't summarize too heavily.