There is a probable link between the stabbing at Gambetta High School and the conflict in the Middle East. It has to be more than just a coincidence that this attack happened on the same day Hamas leaders called for a global "Day of Jihad" and the fact that France has upped its security alert level to the highest position reflects this.
While the conflict between Israel and Palestine has caused domestic tensions in France in the past, an initial investigation has uncovered no immediate evidence that this attack was tied to the events in Israel and the Gaza Strip. While this may appear to be an act of terrorism, people shouldn't rush to hasty assumptions over the motives of this violent act.