Acho que o início disso é explicado nas Resenhas e Lost Stars livros.
After the battle of Jakku a treaty was signed carving up the galaxy. The new republic with some systems and the vestige of the empire with others.
Na Força desperta parece
Some of these vestiges formed into the resurgent new order. It seems but is not totally clear yet, that the rebellion is a separate entity fighting against the first order. In a speech made by General Hux he accuses the Republic of supporting the Rebellion, as in a proxy war. There is very little about the new republic in TFA so we will have to wait to find out what is happening in more detail.
Também é aparente ao final da força que desperta que
The new republic's home system, including it's fleet are lost. The Resistance have lost half their fleet of X-Wings.
Então, qual é a situação política depois do filme?