: Empires are prone to cataclysm when those subject to its code have no say in
: its creation, amendment, or implementation, and certainly when it's
: imposed on people without stake in its intended purpose. Earth has no
: concern over the past, no matter how incredibly relevant it is, and they
: are too arrogant to admit mistakes were made, sending hundreds of
: thousands or millions to their deaths to save face.

You realize that we're saying the exact same thing here, right?
Just how much inertia do you think an empire the size of the UNSC will have? How many trillions of dollars are invested in the outer colonies?

: Those loyal to such insurrectionists, presumably honorable characters, will
: not soon forget who targeted them as their backs were turned. Their forces
: will be in dissaray and authority will be contested, but I argue the
: outcome of this pursuit is just as volatile as sending in infantry
: divisions and destroyer squadrons to a foreign, hostile land.

: The only solution to the situation the colonies face is diplomacy and a
: united front against extremism. You don't need supersoldiers in powered
: armor to achieve that. You need individuals with the will to end two
: centuries of chaos to create what could perhaps be the first interstellar
: republic in thousands of years, if not in the whole of recorded history.

The Spartans themselves aren't the end-all solution, no. They'd have to be used in tandem with greater diplomatic outreach toward those who advocate peaceful change.

The above is an imperfect solution where a perfect solution doesn't exist.

: These people have waited decades for proper, equal representation across
: all levels in the halls of government. Expecting them to wait longer to
: ensure that right is granted to them, then killing off those who wish to
: expedite that process is peeing in the wind.

Expediting that process means that billions get killed. Sitting on your hands and waiting for the diplomats to sort things out means that billions get killed.