What is the climax of "The Last Class"?

“The Last Class” is a story about the personal effects of nationalism and cultural conflicts. Originally written in French, it tells the story of the German takeover of Alsace, a region in France that has historically been claimed by France and by neighboring Germany. The story takes place in a small Alsatian town, primarily in the school that Franz, the protagonist, attends.
The climax of the story occurs when the teacher, Monsieur Hamel, defends France. He praises its language and associates Alsace with France rather than with Germany. The German takeover results in their banning the use of French. The day after the story’s action, school will be taught in German rather than French. Monsieur Hamel will also have to leave Alsace.
Although we do not see Monsieur Hamel deny the order, as it will not take effect until the next day, the author shows him passionately speaking out for French as the world’s most beautiful language. He reads to the students in French and then has them write over and over for their penmanship lesson, “France, Alsace.”
These rebellious acts lead up to the climax, when he writes on the board, “Vive La France!” or “Long Live France!”