The old bilateral "allies list" between two countries is gone. Alliances are now a real multi-country entity with their own members, leader, laws, development, chat and rankings.
Creating an alliance: a country passes the CREATE_ALLIANCE law (name 3-40 chars + color). The founding country is the first member and its president becomes the alliance leader. A country can only be in one alliance at a time.
Joining / leaving: handled through alliance laws — the alliance votes INVITE_COUNTRY, which opens an ACCEPT_JOIN_ALLIANCE vote in the target country. Countries leave via LEAVE_ALLIANCE, get removed via KICK_COUNTRY.
Alliance laws: INVITE_COUNTRY, KICK_COUNTRY, NOMINATE_LEADER, RENAME_ALLIANCE, CHANGE_COLOR, DISSOLVE_ALLIANCE. Each runs a 24h vote and passes at >50% of member presidents. Alliance laws themselves cost nothing for now.
Rejoin cooldown: after leaving an alliance you cannot rejoin that same alliance for 14 days.
Leave cooldown: after leaving or being kicked from an alliance, a country cannot create or join any alliance for 7 days.
Alliance chat: every alliance has its own chat. Membership is derived from role (president / vice-president of a member country, or the alliance leader).
Alliance battle bonus (replaces the old ally bonus): scaled by the alliance's share of total world development. Peak +10% is reached at a 10% world-dev share; the bonus drops 0.5% per percentage point of deviation and is floored at 0% (e.g. share 20% → +5%, share 5% → +7.5%, share 30% → 0%).
Alliance maintenance (paper): each member pays a daily upkeep scaled by its own average development plus 50% of the alliance’s total average development (min 1), out of its own country inventory. A member that can’t pay is suspended — it loses the alliance damage bonus until it pays again (self-heals on the next daily run).
Soft-disbanding: when an alliance loses its last member it isn’t deleted — it becomes disbanded (name kept, marked with a disbanded date, dropped from rankings/map). A disbanded alliance is permanent: it can’t be rejoined or revived.
Alliance rankings: new ranking page for alliances (development, weekly/total damages, population, etc.).
Credit to: user_JHSRL9

And thank you for your attention!