I've had to stop yet another campaign because of the diplomacy AI, which seems utterly determined to attack me at random with little warning. For a while I thought having strong garrisons would deter any attacks by other factions. For a while, this worked, but at enormous expense, as those fleets and armies just love to keep my treasury nice and low. Then, all of a sudden, Sicily and Hungary attacked me for no reason, plunging my treasury into mega-debt, and, myself already at war with the Byzantines, I was forced into a very compromised position. Hence, the termination of my last campaign.

Is there any way to keep afloat in the campaign map, or am I doomed to being forced to fight a capricious AI no matter what?