In many ways, but perhaps the most underappreciated is this: By making it impossible to raise the necessary funding. Only aggression can pull enough money from people to fund the major evils we see in the world, including endless war, massive police state agencies, multi-billion dollar corporate give-aways, pro-corporate "regulation" that favors profits over human and environmental health and which raises consumer costs into the stratosphere, and trillions of dollars in other wasteful, harmful programs.
"The non-aggression principle . . . is an ethical stance which asserts that 'aggression' is inherently illegitimate. 'Aggression' is defined as the 'initiation' of physical force against persons or property, the threat of such, or fraud upon persons or their property. In contrast to pacifism, the non-aggression principle does not preclude violent self-defense."
* There are other branches or versions of classical liberalism; like "anarchism" the term is vague and used in different ways by different groups. I use "classical liberalism" to describe a compassionately pro-freedom mindset common during and for some time after the American revolutionary period.
Anything less than non-aggression is uncivilized. For obvious reasons, aggression is a crime and is categorized in the criminal code as assault, rape, theft, fraud, coercion, and so on.