Mobilisation of German and French troops, WWI, 1914

In 1914, Germany planned to quickly move troops eastward to confront Russia, led by Tsar Nicholas. On August 3rd, German forces advanced through Belgium into France. Meanwhile, French soldiers confidently re-entered Alsace Lorraine, aiming to reclaim it from Germany. Both sides anticipated a short war, expecting decisive battles to conclude it by year's end.

What was the general belief about the duration of the war among both the French and German soldiers?

How many battles did both sides believe would decide the outcome of the war?