Marten van Loon: Starving people to death is also a form of force.
If a person actually confined someone against their will and allowed them to starve that would be aggression against them; but the error is typically to blame the boogeyman at hand (capitalists, big business, voluntaryists) for someone not getting the resources they want or need and suffering from it.
However, it is not aggression to refuse to donate to someone, or even to refuse to contract with them on their terms, or to refuse to associate with them.
If someone comes to harm from not meeting biological needs, it is nonsensical to say "capitalism" or "big business" or whatever their chosen villain is "oppressed" them. If anything, "nature" oppressed them, but that makes little sense when brought out into the open. (DR)
Libertarians understand liberty as being about man-imposed contraints on activity. Statists, particularly statist socialists, see liberty as being about natural constraints. Thus, to libertarians the fact that one must eat, sleep, and have sufficient shelter to survive is irrelevant to liberty. Those are natural constraints, due to the nature of man. Libertarians worry about aggression, that is, constraints imposed by other men by force. On the other hand, statists and socialists tend to claim that needing to eat is a constraint upon liberty. Put another way, this sort of statist believes that, since he cannot flap his arms and fly, he is not free. [HB]
Liberty is about man-made constraints, not natural constraints.
Also see: Exploitation