In Civilization II, they tried to eliminate this tactic by allowing a civilization to force a meeting with you any time you move a unit next to one of theirs. But there was a very simple counter: just don't ever meet with representatives from other civilizations. There was supposed to be a major disadvantage to Republic and Democracy: you have to accept any peace offers.And then, if you ever need to kick someone's butt but the Congress overrules it, just start a revolution, declare war, and continue enjoying benefits of democracy the very next turn! The only thing you need to watch out for is to never study Communism, which disables the Pyramids effect, and luckily, it sits pretty high up in the science tree and you don't really need it. That basically allows democracy (a game breaker government all in itself) about 3000 BC. With just Masonry technology needed to build them, they allow you to change your government at whim, to any type of government (even if you haven't yet researched it), without an anarchy period.
The original Civilization had the Pyramids wonder."Power Democracy" takes a bit of fine-tuning to pull off correctly, but it'll allow you to run away with the game if you manage it right. The only downside (a Senate that would veto war declarations and try to force your civilization to make peace during negotiations whenever possible) was negated by the fact that the AI was already suicidally aggressive anyway, and that the player could use spies and their ludicrous piles of money to subvert enemy cities even when not at war. The upshot of this was that a civilization with these two governments could effectively pour the vast majority of its taxes into luxuries and watch as all of their cities turned into economic powerhouses over a few turns, continuously pump out trade caravans, and use the absurd amounts of money they would soon have in order to rush build any and all units and improvements necessary. Meanwhile, trade caravans could be built and sent to foreign cities for absolutely ludicrous one-time cash windfalls. While other governments simply gave resource gathering bonuses to cities with enough happy citizens, Republic and Democracy governments got those bonuses by default, and happiness allowed for instantaneous population growth instead.