I agree that the AI can be very strange when deciding to go to war. However, I have noticed some thing about the AI that support that it isn't totaly random.
1. If it is a suprise attack, they usualy have huge masses of troops at your border and think they are going to benefit.
2. Making a military alliance against you is not just the computer deciding to gang up on you. Fact is, you should have tried to bribe those countries first.
3. Just because they don't have any real relationship with you and reside on a different continent, doesn't mean they should be peacefull with you.
My favorite tactic with Civ III is all out war. I only shift to the peacful Govs. like Republic and Democracy if I am already huge, or if I just had a really bad start and I can't seem to catch up military wise. Anyhow, I too have been the victim of a massive pile on. It starts with the huge guy next door, and then next thing you know everyone is against me. But there are ways out of this, it isn't impossible to turn this against the computer. First, just make as many alliances as possible ASAP after being attacted. Then try to make peace with anyone who will allow it as soon as possible untill you are at peace with everyone. This can take a long time but it is possible. I have had games where I was able to get out of the huge world war, and sit back in my peaceful democracy while the rest of the world killed itself in a rollercoaster of alliances and counteralliances. All this started by my neighbor attacking me.
And on the flip side, when I am a raging behemouth I will declare war on any republic/democracy in the world. No reason necessary. Why let them have the advantages of a government like that without making them suffer the war weariness? Perhaps the AI sees this also.
And who cares if you were so nice to one of the AIs and then they decided to go to war with you. I never put too much faith in allies anyhow. They will never give you a fair trade for longer than 20 turns, and usualy it is me helping them not them helping me. I could be wrong but I can usualy pull off a trade with someone who is furious with me as well as one who is polite. Changes in heart happen in real life too, but the accelarated time of Civ III makes it seem stupid, when it really isn't that bad. Hard to immagine that just over half a century ago the US was fighting Germany and Japan while helping to defend amoungst others the Republic of China. Things change. And besides it is more fun to crush a pathetic civ that takes your cherity and then stabs you in the back.
