"They have only themselves to blame," Thurgood-Smythe said. "We gave them peace and they gave us war. We will now show them the high price that must be paid for that decision. When we are done with them there will be peace in the galaxy forever. They have forgotten that they are the children of Earth, that we built the commonwealth of planets for their sakes. They have forgotten what it cost to terraform all of their planets to make them suitable for occupation by Mankind, the cost in lives and money. They have rebelled against our gentle hand of rule. We shall now clench this hand into a fist and they shall be punished. They started this rebellion, this war — but we will finish it."
— Starworld by Harry Harrison
"On Earth, there is no poverty, no crime, no war. You look out the window of Starfleet Headquarters and you see paradise. Well, it's easy to be a saint in paradise. But the Maquis do not live in paradise. Out there in the Demilitarized Zone, all the problems haven't been solved yet. Out there, there are no saints — just people. Angry, scared, determined people who are going to do whatever it takes to survive, whether it meets with Federation approval or not!"
— Sisko, Star Trek: Deep Space Nine ("The Maquis, Part II")
For all the talk of the Jovian menace, everyone knew that the greatest threat to peace in the Solar System was Earth itself. The orbiting A-bomb platforms of Spacefleet had made wars of conquest obsolete, but not the pressures that caused them. Cold War hostilities threatened to erupt anew on other worlds, while young superpowers like India and Brazil were flexing their might. Africans and Asians who had been freed from the yoke of colonialism were establishing colonies on Venus and Mars, seeking to depose civilizations they viewed as primitive or decadent. Famine loomed on Earth with over seven billion people crammed into megacities and not enough arable land to feed them. Scientists had invented the birth control pill but it had little effect on the morals of society. It was more politically expedient to support off-world emigration than unpopular measures of population control.
If there is one lesson to be learned from the history of human society's colonization of distant lands, it is that remote rule proves only sustainable under absolute tyranny, and all the bloodshed that entails. A growing desire for independence from a far-off homeland is inevitable, and conflict in the pursuit of it a given. This will be just as true for our off-world colonies as it was for America and Africa centuries ago. If we do not establish a workable solution now, Earth-bound humanity and space-based humanity may well become locked in a cold war spanning light years.
— Interplanetary Polities tech blurb, Terra Invicta
"We used metal for their ships that could have repaired our homes. We gave them food and water for their supplies that could have fed our hungry. Our scientists worked on colonial technology when they could have been solving our own problems. We poured our blood, sweat and tears into the Aeneas Project, and now that the time has come for our repayment, those selfish bastards are trying to back out on the deal!"
— Karlin (somewhat of a biased source), The Aeneas War
(No Man's Sky fanfiction)
(No Man's Sky fanfiction)