I know that the AI civs love to attack whatever military rates as weakest. If you tend to focus on research early on (as I do) and don't bother putting a fleet or two out there, they will always attack you. And while I haven't played long enough to say for sure, I'm pretty sure you're right about a well-balanced economy making everyone else angry.

Depending on how many civs your playing against, try and keep yourself in the top 3 or 4 in military rating. The big fish always go for the little ones first, also getting an alliance with one of the more powerful civs is a good tactic, even if you intend on wiping them out eventually.

I too go for a economic and research route early game myself, my trick to keep my military score up is, firstly do what ya can to get a military resource and max it out a.s.a.p, then get to about the 5th level of your chosen weapon type and load up a couple of cargo hulls with them and don't bother with engines. You won't use them for combat per se, but they will push your military rating up higher, even though it is a bit of bluff.

When ya done with those cargo ships and if they have seen action and lived, turn them into armed freighter's, especially if they have leveled up a bit.

Another little theory i have and yet to prove either way is that whomever manages to build Tri Quon Training seems to not get attacked as much, at least early in the game. This is yet to be proven but it certainly helps out regardless.

Hope this helps

The Spin Control Center is what makes it for me, like Wyndstar suggested. I also concentrate on developing a stable economy and a fast research pace early on. But if I wait too long on military development, I always get attacked.

So after about 30 turns, I'll fast research the whole Diplomacy tree, up to Total Majesty; then shift focus on my highest production planet to social production to build a Spin Control center; then just build Defenders on that planet until it's full. That usually puts me into second place militarily, and fairly often into first: no attacks after that. In fact, in 1.6, taking care of Diplomacy and Spin Control at this stage usually leaves me ready to get access to the other planet types in relatively short order: Extreme Colonization is relatively cheap by then.

The other races do take that as a challenge, and start building up their military, so with this strategy you'll have to return to military production at some point in the mid-game. But by that time, you'll have a solid economic base, are usually pretty far along in research and have a bunch of strategic options. The best thing about Spin Control is that filling up the relevant planet with medium ships (medium hulls, 10 or so weapons, 10 or so weapons) puts you far in the lead militarily, and can give you a breather until you're ready to do something decisive.

Just my two cents,

Alex

somehow it bothers me to build all those crappy defenders early on, and I'd rather build up my planets or build colonizers or constructors. In my latest game as the Altarians on maso, DA1.6, large galaxy all abundant, I built a strong economy early, then bribed the other civs to go to war with each other. I also traded an economic treaty for a research treaty and a ton of crappy terran fighters. I was next to last or last in military strenght until the late game, but I was never attacked because everyone was "too busy" blowing each other out of space. They did ask me for money though, but I could easily afford it. I only built the spin control center late in the game, when a conquest victory seemed practically assured. That worked for me this time.