Themken: That is exactly what I felt it was but with some twists and improvements. I suspect they made SMAC right after Civ2.
Not an expert on playing this and do not even have SMAX. Maybe I just play it wrong but for me it is just one long war.
The following is directed at games where these wars are between AI-AI Factions, if your problem is people choosing Vendetta against you, then that calls for other options - mostly "buying" peace until you can buff up your defences and/or finding Allies. A big topic but I'll focus on the question of "general" war-mongery here.
Two things - one specific to your problem and one only associated with it.
Usually if you contact a faction you have at least "Blood Truce" with, one of the dialogue options will be "Call off your Vendetta on my friend...".
When you ask for this, you will either: get a message saying something like It is xxxxx who has pressed this Vendetta, or you will get a message saying "So be it. As a personal favour to you I'll call off the vendetta." [or thereabouts]
Now I am not sure if this ability to ALWAYS force an end to an AI on AI Vendetta is difficulty level dependent, but it always works in my games [I don't play at the highest level].
If you only know one of the Factions involved in the Vendetta, then the Faction you DO know will have the Com frequency for the other and will most likely trade it/sell it to you. [A useful option regardless of Vendetta status.]
Now this might only buy ten turns of peace between these two AI's [Blood Truce only lasts so long] but if you are looking to cut down on total numbers of wars, or if you think Faction A or B being at peace will be to your advantage, then it costs you nothing and may be worthwhile. Just note that a particularly war-like Faction [Believers, Hive, etc] now suddenly at peace may look YOUR way for their expansion! ;)
The second point I'd bring up is that one of the MOST useful early Projects, if you are looking for a more peaceful game is "The Empath Guild" which you can start with only an E3 tech [Centauri Empathy I believe] and which gives you an infiltrator in every faction [very detailed info screens for the other Factions], gives you the Comm Frequency for any Factions that you haven't met [good for diplomacy, tech trading, general trade and alliances] and also gives you 50% more votes in the council than your population would normally get, which means it is likely that YOU can become Governor and get the increased trade associated with that.
[Note that this bonus also stacks with other Projects that increase one's Council vote and with Lal's Faction bonus, making him almost unbeatable unless everyone else votes for one competitor].
Even for players looking to run a Conquest game, this is invaluable since you can peek into EVERY base a Faction has, to scope out their defences, without having to get a Probe team into that particular city/Faction.
So see if you can get one or the other Faction to end or at least delay their Vendettas against another AI and make your games at least a little more peaceful this way... :)
Lasivern