Instead of betraying his country in May 1779 he simply resigns his commission and stays with his wife in Philadelphia for the remainder of the war.
Arnold didn't betray his country....he betrayed the rebellious colonials...why would he resign?
Arnold did not betray the revolution, the revolution screwed him in payments and career posibilties with gates taking credit all his victories and congress being dicks with their plans, he simple change sides who was to common in europe for generals and solider to change sided in war like know we change soccer Coach and player between season.
If he did decided steep down the revolution but not rejoing the british...the irony is that the continental congress will declare him either a deserter or a traitor and he will be in worse problems that OTL...But history is written by the victors
Instead of betraying his country in May 1779 he simply resigns his commission and stays with his wife in Philadelphia for the remainder of the war.