Germany, because it had an alliance with Austria, told Russia to stop mobilizing, which Russia failed to do, so then Germany mobilized its own army, declared war on Russia, cemented an alliance with the Ottomans, and then declared war on France, because, you know, France.
奥地利的盟国德国， 要求俄罗斯停止调遣军队， 俄罗斯当然是拒绝的，于是德国 也开始调集自己的军队， 与奥斯曼土耳其结成同盟， 向俄罗斯宣战， 然后又向法国宣战， 法国嘛，你懂的。