The Schieffen Plan
The issues of potentially having to fight a war on two fronts had become a real problem after the Dual Entente was signed in 1893. In 1905 von Schlieffen devised a solution to this issue.
Under the Schlieffen Plan, France would be attacked first and defeated within six weeks. They would expect the attack to come from the Alsace-Lorraine region, where there was a common border and wouldn't expect one to come through neutral Belgium and Netherlands and as such would be taken by surprise and quickly defeated.
Because of the size of Russia, it would take longer to them to mobilise, and so Germany could use the same army to next defeat Russia. Despite dying in 1912, his plan was adapted in 1914, with Germany stacking through Belgium only. So confident was Germany that the Kaiser is quoted to have said 'Lunch in Paris, dinner in St Petersburg'.
Under the Schlieffen Plan, France would be attacked first and defeated within six weeks. They would expect the attack to come from the Alsace-Lorraine region, where there was a common border and wouldn't expect one to come through neutral Belgium and Netherlands and as such would be taken by surprise and quickly defeated.
Because of the size of Russia, it would take longer to them to mobilise, and so Germany could use the same army to next defeat Russia. Despite dying in 1912, his plan was adapted in 1914, with Germany stacking through Belgium only. So confident was Germany that the Kaiser is quoted to have said 'Lunch in Paris, dinner in St Petersburg'.