I always seem to get attacked for no reason

I bought Beyond Earth when it came out and have tried playing a couple games. The game doesn't really seem to grab me and I've sort of reverted to Civ 5.

Anyway, each game I start 2, 3 or more civs always end up attacking me, maybe 4-5 cities (that I've built) into the game. There is still a ton of open space around and I'm sure to make a couple friends, but don't really act aggressively towards anyone. My expansion doesn't get anywhere near their cities.

I prefer early building over conquest, and in terms of the colonization of an alien planet, that approach is realistic in my mind - war wouldn't happen unless there is a very good reason for it, at least during the initial stages of colonization.

I make sure I have 1 military unit in each city or so, and I focus on building up my realm, but then.. yeah, I always get attacked by multiple civs. It seems unrealistic and the suspension of disbelief factor vanishes and I stop playing.

I am playing on normal difficulty. This never seems to happen in Civ 5 - I can build up usually quite a bit before I am attacked - surrounding civs usually don't seem to care unless you get in their face.

So what am I doing wrong? Was this a coincidence? Do I need a larger army? One thing I have been doing is avoiding conflict - so when I'm asked "join our war", I always say "Thanks, but no thanks". Is that it? Do I need to divvy up the other civs into friends and enemies rather early? I would prefer to make friends and leave everyone else "neutral", if possible.

What's your Affinity like? People don't like it when you progress technologically in one area. The AI might take offense to your pursuit of Supremacy or Harmony.

Also, don't put military units in your city. They contribute negligible bonuses to the city's defence, they'll die if the city is taken. In fact you don't need one in every city. The AI is quite bad at doing a war of conquest, so you can get away with a few token troops so long as they're the good ones.

As for making friends, the AI doesn't like you at all, no matter what you do. Sure they look all friendly and cheerful but they'll go to war at the drop of a hat or condemn you and call you an oath-breaker as soon as you make an oath. Seriously I launched a satellite once and they said "Don't launch in our territory" so I said "Ok, I won't do that."
Next turn, they condemn me for breaking my promise not to launch any satellites over their borders.

Whilst the diplomacy thing in BE is a bit abysmal compared to previous games, the next expansion is hopefully gonna fix that. More importantly, these are all competing nations after all, and honestly yeah basically everyone hates each others' guts. Even back when they were on Earth.

I play on Soyuz, and I'd be lucky to make one friend.

Bribing your neighbors into war with each other is a good way to get away with not having too much military (And 1 unit per city is "not having too much military"). Other than that you can also scout the enemies lands and make sure to see when they arm up. If you're the weakest faction around then you can be sure that these units are going to be thrown at you at one point.

I don't think it's "unrealistic" to assume that people would attack each other rather soon though. On the new planet there aren't really that many diplomatic repercussions for that, so why wait for that other nation that is clearly developing other values than we are to grow stronger when it seems like we can just end the danger before it even arises? An early war may prevent a lot of trouble later.

I've often heard about players bribing the AI into wars but it's never worked for me. Either they will not consider it at all or the want so much I would be a fool to pay them. Maybe because it's never worked when I've tried it I don't try it often so I'm not seeing the times it would work.

Anyway, since this game has free unit upgrades there's really no excuse for not having a military.

All the BE games where the AIs gang up on me early have been games where I neglected my military. If you expand fast without building up your military, the AI loves to attack you, especially if expand in the direction of the AI. Your bases don't have to be close to the AI, just close enough that the AI feels that you are stealing land that it wanted to expand towards, then the AI will mark you as a target for conquest.

Also, check the diplo modifiers in your foreign policy screen. if a sponsor has a lot of red statements, then they are more likely to attack you and if 2 or more sponsors hate you, it is likely that they will join a war against you.