The decision comes down to complicated motives. For Ned, he wants to stay in the North, but also we find out that he's afraid he's not up to the job and doesn't want the responsibility any more than he ever has. He's justifies this by stating that Robert, to whom he hasn't really spoken in years, is his friend and will understand. Later, we find he fears not returning like the rest of his family. He then decides to go when it becomes apparent that the Lannisters are a threat to Robert. For