Played a "Hard" game as Wild Walkers and went for a diplomatic victory. Made peace with everyone, then alliances with everyone, til the end of the game. At some points some allies dropped to cold war with me, in which case I just re-offered alliance and they immediately accepted. At all times my military was _massively_ weaker than everyone else's, and I was losing on every single victory type (except was close in scientific) throughout the game. But no one ever attacked me. Moreover, apparently no one every attacked anyone else, since I was never called to war through any of my alliances. (One really strange thing--when a faction would decide unilaterally to break their alliance with me, it was always cast as them "reacting" to "my" breaking the alliance, though I had done no such thing.)



Just kind of coasted to the end of the game and won.



Does AI get more aggressive and less eager for alliances at higher difficulties?



Do alliances actually get you into your allies' wars as I am assuming?

The AI does not get more aggressive on serious, they just let you win diplomatically, which is easily the least "functional" and fun victory condition.



And I do not recall a single instance of an ally asking me or demanding that I declare war on anyone, so I don't think that mechanic exists. What I do think is the case is that allies are a lot more likely to accept declaring war on an AI you suggest, because of your alliance.

In Endless Space, if you formed an alliance, then all members of the alliance were forced to have the same relation to factions outside the alliance; thus, if your ally went to war, you were placed in a state of war, too.



In Endless Legend, that is not the case; it's possible for your ally to be at war without you being at war. If you want to see other players' relations to each other, go to the diplomacy screen, mouse-over another player, and click on the circular-double-arrow icon in the top-right of their info panel to see the screen from their perspective.