The Starks are a family out of step - and out of touch - with the world they live in. They represent the traditional "heroes" of high fantasy - honorable, just, true, romantic, and loyal.uses the Starks to turn the very idea of "fair" on its head, and thus makes a subtle dig on his readers who demand fairness and balance in their entertainment, that their chosen heroes win and the bad guys get theirs.
To break down Robb's decisions:
Robb Stark's rebellion = Just. The ultimate "just war" started out of a righteous sense of protection and revenge, not a scheme for power. This legitimized Robb's crown and inspired his armies on to victory after victory.
Robb's punishment of Catelyn = Crazy. Here we see the flaw in Stark logic, that Stark justice is incompatible with itself. Robb cannot be simultaneously just and loyal to his family. He cannot be wise and beloved at the same time. He fails to strike a wise balance, making himself look weak. Lord Karstark and Tywin Lannister both lose respect for Robb, laying the seeds for everything that is to come.
Robb's Wedding to Jeyne = Rash. You might feel that Robb is being true to his heart, and this reckless love is honorable and attractive - except that he is a state leader! Robb's oath is the pledge of his kingdom. As much as I despise the man, Lord Frey took considerable risk on his kingdom by siding with Robb in open rebellion against King's Landing. Robb's broken oath is not something a king can simply apologize for. An honorable man does what is right, not what he wants. In marrying Jeyne, Robb risks the lives of his entire army and his kingdom.
Robb's beheading of Karstark = Pigheaded. Robb became overly worried about his reputation and not what is just. Karstark's crimes where clearly similiar to Catelyn's, yet one gets a scolding and the other beheaded.
Robb appealing to Lord Frey for an army = Stupid. Enough said, we know how that decision worked out. Please note that the Red Wedding is based on real history - the Black Dinner of 1440, when the Earl of Douglas and his brother were murdered under the same circumstances.
Now, I don't agree with anyone who takes the stance "Life ain't fair, especially in Westeros." Martin is brutally fair, all of his characters will meet their end in due time. Don't get too comfortable with any one character.More questions on Game of Thrones Season 3: