Contrary to popular belief, the invasion and occupation of any particular nation is not a mere exercise of military might. It also, by necessity, involves the destruction or overrunning and eventual replacement of all the above mentioned institutions.
The most extreme modern-day example of this was the US invasion of Iraq, where Iraqi institutions from top to bottom were either entirely destroyed and replaced, or taken over by the Coalition Provisional Authority (CPA). The CPA was literally headed by an American, Paul Bremer, who, far from being a military man, was instead drawn from the US State Department and a background of chairing corporate-financier boards of directors.
The CPA assumed responsibility for all aspects of life in Iraq, from the privatization of Iraq’s economy, to “reconstruction,” to reorganizing the nation socially, politically, and economically.