The government used to be civilian controlled, led by the 3 biggest factions , and the speaker, a person who was a defacto president/leader , it was called the consensus, with the Vanguard acting has the military on behalf of the consensus But after the Red War, in which a ruthless faction of Cabal led by Dominus Ghaul attacked the city to claim the Traveler, the speaker was killed , leaving just the factions and the Vanguard The two sides still worked together in lock step, untill Ikora Rey offered Eliksni refugees sanctuary in the city without the factions approval that started a drastic devide, in which the leader of the future war cult planned a coup to overthrow and replace the Vanguard , and kill the Eliksni refugees, would have led to a civil war if she didn't get herself killed trying to use the vex to acomplish her plan , and the remaining faction members were exiled Now the City is a military dictatorship , but Ikora and Zavala are not dictators , they are protectors at heart Bungie has ignored the logistical vacuum and probable disaster those events caused however, conveniently

It is currently a military dictatorship, it use to be governed by the "Consensus". The Consensus was 3 factions that have long since disbanded, with many of its members being sent into exile.

The Vanguard are the Eggmen... we're "child soldiers".

So. The Vanguard before the Red War and Forsaken was purely Military. As they made up the Military with Guardians. Zavala, Ikora, and Cayde-6 were the Rep and Leaders for the Guardian Factions(Titan, Warlock,Hunter) New Monarchy, Dead Orbit, and FWC were the Human Side of Government, with the Speaker being the Head of the government as they "Spoke" to the Traveler. New Monarchy tried to start a Coup to remove Speaker from Leadership. Guardians Squashed it. Then FWC, with New Monarchy tried to Remove the Eliksni by force, even though they were under Vanguard Protection. So FWC and NM tried to and Failed, then were told to Leave and be Exiles. Dead Orbit left on their Own Accord. Now the Government is the Vanguard. Zavala, Ikora being the Heads. Osiris being a Adviser, Saladin being a Rep for Humanity with the Cabal, and Saint-14 being a Rep with the Eliksni. Edit: in Season of the Splicer, Zavala and Ikora declared Martial Law.