What is the internal conflict in dear John?

The internal conflict in Dear John is John Tyree's struggle to balance his love for Savannah Curtis and his duty to the military. He is torn between his desire to be with Savannah and his sense of obligation to his country.

John initially chooses to stay in the military, but he is eventually discharged after being severely injured in combat. This allows him to return to Savannah, but he is still struggling with the emotional scars of his experiences. He feels guilty about leaving his fellow soldiers behind and worries that he will not be able to provide for Savannah.

John's internal conflict is ultimately resolved when he realizes that he can find fulfillment in both his personal life and his military career. He marries Savannah and they start a family, but he also continues to serve in the military on a part-time basis. This allows him to balance his love for his family with his sense of duty to his country.