Caravans should still come after the siege, at least until one (or possibly more) caravans disappear, or one caravan flees after being attacked. They shouldn't magically know you are being sieged.
Yeah, this would make it more realistic.
Also, it should be based on the size of a siege. If the siege is a horde of 200 goblins led by their king with legendary troll strike squads around the perimeter, fine, don't send caravans. But if it's a basic 30 goblin siege against a fortress with no military, just send in more guards with the caravan and beat the everliving s*** out of the goblins.
Eh, now you have contradicted yourself a bit.
How should other civs know about the actual size of the sieging army?
If they flee, of course. If they just die, they send scouts instead of caravans (or more scouts WITH the next caravan) who report any sieges (of course, this would mean a year without a human/dwarven caravan after the siege ended, but it makes sense).
Here's what I think: All caravans start coming with scouts. Said scouts have high agility. If the scout sees enemies, he runs away and reports such. (This, of course, requires scouts to have a specific LoS). If all the scouts do not report, the civilization assumes the worst and simply sends a squad of scouts instead of a caravan next year, or sends more scouts/guards with the caravan (depends on your relations with them).
Caravans should still come after the siege, at least until one (or possibly more) caravans disappear, or one caravan flees after being attacked. They shouldn't magically know you are being sieged.
Also, it should be based on the size of a siege. If the siege is a horde of 200 goblins led by their king with legendary troll strike squads around the perimeter, fine, don't send caravans. But if it's a basic 30 goblin siege against a fortress with no military, just send in more guards with the caravan and beat the everliving s*** out of the goblins.
A Carivan is used to fighting bandits, but why would they want to break a siege?
It should depend on the size of the Carivan as well.
Also not knowing you been sieged? They should run as soon as they see the siege which should be as soon as the scouts spot the siege unless the enemy is intent on hiding so they can catch a few of your carivans.
First off, learn to spell. Your posts make me CRINGE. Second of all, the caravan guards have high attributes and are quite adept at killing multiple goblin ambushes at once, so breaking a siege is not far beyond a regular caravan's defenses, let alone a buffed up one. If you are going to comment on WHY they would want to break a siege, it's simple. Money. Dwarves obviously would give you more help, especially if the king/high ranking nobles were there, because it is their land. Humans would have enough interest, depending on the profit they make each year, to send more and stronger guards to ensure their profit (IE: You give humans a lot of money in trades, they hire more guards for the next year to keep up the profit). Elves... probably not that helpful anyway.
Also, why would scouts spot the siege immediatly? For gameplay reasons, I am fine with you being able to have infinite lines of sight so that the game is playable, but sieges and caravans both should not be psychic about all the aspects of your fortress.