If you decide not to fight the dengi king yourself, The Scourge of Raana plays out like a series of society-shattering events (like a combination of Alien Vermin/The Rise of The Confed./The Red Tide) that are meant to leave Ikaanos in a "Dying World" state, if it even survives.
It's part of the lore that leads up to MoR2.
If don't want to risk that, or have a very weak republic, my recommendation is to either wait or never press that button. At least it's optional.
But again, expect more fleshed-out approaches in 0.8.4+.