How do you defend Germany in a world war 1 debate?

Germany did not start World War I. They only declared war on Russia because Russia mobilized troops toward the German border because Russia got involved in a territorial dispute between Austria, Germany's ally, and Serbia. Germany most likely would have ignored a fight between the monstrous Austria and little, tiny Serbia, but Russia made a threatening move on Germany which the couldn't ignore. Germany invaded France, but France had already declared war on Germany after Germany went to war with Russia, France's ally. During a war between to nations with a border, one is bound to invade the other and Germany made the first move. There isn't really an excuse for Germany's invasion of Belgium, so if it is mentioned in the debate, I'd suggest BSing an answer and moving on quickly.