Quote Originally Posted by Razor1952
I find that hard to reconcile, my personal experience is that diplomacy works if you cultivate your friends. As Venice I was able to go from deceitful where lots of factions declared on me to reliable where everyone wants to be my friend. Of course I bribe the pope(100x100) and did the same for Milan and france and Hre early on till I made the mistake of travelling through HRE territory without consent. I never had to fight a catholic army which was not excommed.

Pretty much all catholic factions are so-so or above relations(except Milan which I had to take out the local cities to stategically leave with a few choke points to defend if necessary(after they were excommed of course). Even HRE now at peace and amiable.

Now 30 provinces and the mongols have arrived and Jerusalem and most of nearby provinces are heavily defended and upgraded. Only the Turks and Moors are at war with me (aside from a crippled Milan) and everyone else is happy with me.

I turned my young doge +8 dread down to +2 dread only in about 20 turns. he's still in his 40's. That probably did more for my reputation than anything else.

Unfortunately even playing to preserve reputation and relations my game could easily be over before gunpowder.
Unless you've enabled the diplomacy variables, what you've described is not due to diplomacy working correctly. The variables control at what level of reputation and relationship the AI factions will trust you and thus respect your alliance with them, and are set by default so they never will. If you haven't enabled diplomacy, then any experiences of the AI seeming to keep alliances are typically due to your overall military presence being so great that they fear to attack you, or that you have a strong enough military border presence against any given faction that they do not feel they can successfully attack.

While I understand that the AI does not really feel things, of course, what I am talking about are the various triggers in descr_campaign_ai_db.xml that tell the AI when and how to attack. One of the primary conditions is to check military strength nationally and locally of the target, to gauge if a war could be profitable or winnable. If you have a strong enough military presence, it would essentially make the AI understand that it could never win, and thus not attack. The fact that you say your game could still be over before gunpowder indicates that you probably have a very large military, or you'd not have amassed territory so quickly... which of course makes it all the more likely that your power is the factor staving off the AI aggression as opposed to anything else. In my experience w/ diplomacy disabled (i.e. out of the box game) your border defense is the single biggest factor that determines whether you keep peace with any given AI faction.