Provoking war?

From the trade screen, you can ask another civ to "declare war" etc. Also you start a war with an AI civ by physically attacking them. I definitely provoke the AI into declaring war on me first on a regular basis. Hope that helps.

EDIT: I always play with the AI on Intelligent. If you are playing at a lower level than that, the AI plays dumb(er).

What kind of ships do you park next to their planets ? Put a few troop transports nearby, should work..

I've found no effective way to destabilize a relationship, but once a system of alliances begins to form, you can really get creative with starting an intergalactic war. For example, if you get a civ 1 to declare war on civ 2, civ 2's allies will all attack civ 1, subsequently causing civ 1's allies to attack civ 2's allies, forcing civ 2 to fight civ 1's allies. PRESTO!! Anarchy in a can!! (That phrase is trademarked)

PS- If you don't have enough support in the senate to declare war, ally yourself with a minor civ. The little fella' will get attacked sometime or other, and then you have the chance to declare war "vote-free."

PRESTO!! Anarchy in a can!! (That phrase is trademarked)

But that's not anarchy... that's just a bunch of governments fighting each other, which is quite the opposite of anarchy.

Beat me to it.

First of all, my allies are trading with them, so they do not show up under the attack window. They were surrounded by 20 logistic maxed fleets of medium hull ships and a fleet of two lucky rangers. I kept asking for tribute with no response, and I did a trade embargo on them. And allies do not automatically come to your aid if you start the war. I also supported the current civ they are at war with by giving them a fleet of old ships right by the Yor planet. The AI is on Intelligent.

Put some troop transports, and an inlfuence base near his planets.

To get two races who are on good terms with each other to fight, try the same thing only once you position the transports and base, then give them to the other AI. (I haven't actually tried this yet.)

I second the Ally with a minor tactic...

went through an entire galaxy with 10 times the military firepower of anyone else and never had to decare war... the AI every other week or so declared war on my minor ally...

I was allied with the torean. They attacked a minor race and said i was bound to help them or the allience was off. I had plenty of trade with the Torean so didn't want to upset them. I agreed. I was then annihalated by 6 other races.

The toreans meanwhile took the minor race planet and (somehow) made peace with everyone. Despite my high diplomacy and military strength no one would negotiate peace with me (they kept moaning about how i was too evil to exist). As soon as I had been ground down by endless waves of fleets the Torean also declared war on me. This meant I was fighting every other civilization.

It was over pretty quick.

That was the end of my first attempt at an alliance victory.

The moral of the story is that the Torians, while claiming a good alignment are actually a bunch of b*****ds.

A little way into the game the AI started building up fleets while I concentrated on diplomacy to keep people sweet. Because I didn't have a military the Arceans relations with me went from neutral to angry. I scrabbled to build a defence fleet but that still wasn't enough he was *still* angry with me. So I decided to take the initative and start the war on my own terms before they attacked me anyway. I spent a little while building my fleet and trading for tech until I was ready. The Arceans still held off declaring war on me, but as soon as I built a influence base and stole some of his space he declared war on me.

So yes, influence bases. Even if they don't attack you, you can steal all their space until they do, or start rebelling.