Rama going to the Forest for fourteen years is the divine plan. It was predestined that Rama should go to forest for doing so many things like Ahalya Vimukti, destroying the demons there and protecting the saints and sages. And it was only an excuse, to get equipped by Vishwamitra for the future Ravana Vadha (killing).
Kaikeyi the mother of Bharata who was instrumental in sending Rama on the advise of Mandara is inspired by Rishi Sankalpa and Daiva Sankalpa.