No, the President doesn't have to be a veteran, but it would help if he had some sense of how dangerous a game he is playing, along with Netanyahu. What finally had the Soviet Empire fall were the insane foreign wars they engaged in, bankruptcy had to follow.
War is the enemy not each other. Never should have murdered those Iranian leaders, now peace is not going to be on the table, for a long time. But then, I imagine Trump sees the Iran War as working for him in some way or other.