[DocTomoe]

The first function of a state is to ensure the continued existence of the state. Which is threatened a lot more by civil uprisings as compared to an external actor, especially in a time when international relations are relatively stable (current security events being the formerly-normal that is today's extreme). Another "storm on the Capitol" is so much more damaging to the US as it exists today as compared to a border skirmish with the Chinese over Taiwan.

[FortiDude]

The state wouldn't fear civil uprising if it made its citizens' lives half decent

[DocTomoe]

Then it would take away from other powerful factions, which will then ... overthrow the state. The idea of an unified, altruistic populus which will put the average wellbeing over their own is utopian - in both senses of the word.

Reading suggestion: The Dictator's Handbook: Why Bad Behavior is Almost Always Good Politics, by Bruce Bueno de Mesquita and Alastair Smith