You vote. They age. But the games are very different (Kremlin has cards, dice, the secret influence... iSdK has no randomness at all, actions are "drafted" from a common open pool, there's area majority...).
Also how big is the negotiation part of this game?
As big as you allow it to be. Usually enough to be a crucial part of the game, but still less than what you get in a "trading" game (like "Traders of Genoa").