Originally Posted by Librarian
However, since such fixed positions with the stores necessary to weather a siege of some length are the source of the supplies of the besiegers, there's no reason to assume a long siege. Easier to bypass and come back later.
Historically, sieges were raised when
* other requirements caused the besieging forces to move
* a relief force was near enough to threaten to or actually engage the besiegers (probably N/A here)
* sickness weakened the besiegers
* besiegers were unable to forage for enough supplies to stay
* besiegers were unable to cut off the besieged from resupply, and finally gave up
* a traitor opens a gate and the redoubt falls
* sickness in the strong point reduced the defenders beyond the ability to defend
* lack of supplies weakens the defenders beyond the ability to defend, as suggested here
* a message is received by the defenders ordering them to surrender (probably N/A here)
* a military or negotiated resolution is reached at a higher level, causing hostilities to cease. (probably N/A here)
ETA - 1 more, exemplified by Masada - garrison suicides rather than yield.
(And I did omit 'attackers win by assault' - climb the walls, break the gates, undermine the walls/towers, etc - and kill some or all of the defenders. No more siege after that.)
I don't recall reading of any where the besieged managed to sally and break the siege, but that's a possibility. As you point out, tough for a family of 4 to do against a larger force.
Your premise rests on a crucial assumption; that your attackers are interested in your material goods. As Islamic wars often prove, sometimes money / material necessity has nothing to do with it.
I used the example of the South African farmers for this reason. The raiding parties laying siege to the white farmers don't give a crap about farming or storehouses of food. They're attacking because they want to commit racial genocide. An attacker motivated because your religion or family represents a target won't go away because you have defenses or extensive food stores . They could care less.
The case of Nazi Germany, Soviet Russia, the Balkans, the LA Riots, and other examples of racially motivated attacks show that an enemy like that wont stop until you-or they-are dead, period.Without a police or government force to stop it, people in a SHTF crisis will group along ethnic lines and perpetrate acts of racial violence with impunity. That's a bigger threat then roving raiders:at least raiders will pragmatically leave you alone if they get access to resources or find you a too difficult target.A squad of armed racist degenerates will hunt you down until someone dies.