Greek Orthodox Priest Shot In Lyon As New Violence Rattles France

A Greek Orthodox priest was shot in Lyon, France, and is in critical condition. This incident follows a recent attack in Nice where three people were killed. Tensions are high due to the republishing of Charlie Hebdo's images of Muhammad, which previously led to a deadly attack in 2015. Recently, a Paris teacher was killed after showing these images in class.

How did the tensions between France and Muslim nations escalate recently?

What incident involving a teacher occurred two weeks prior to the priest's shooting?