Nicky deserves almost as much blame as The Kaiser for starting the war, with his mobilization, despite the Kaiser begging him to stop it.
None of them, not Nicholas, George, or Wilhelm, were really calling the shots.
They were useful idiots, used by the people who wanted war.
Nicky heard this and promised "cousin Willie" that he wouldn't mobilize on Germany's border which Wilhelm II was prepared to accept. Russia's generals then told Nicholas II that Russia had no plan for partial mobilization. It was either full mobilization or no mobilization. They piled the pressure on Nicholas II and got him to fully mobilize thus breaking his promise to Wilhelm II and furthermore making it look like his promise had been an act of bad faith all along....that he'd intended to stab Germany in the back all along and wanted to destroy it. Germany immediately went to war in response.
ie Germany was not the aggressor. It was not looking to dominate the continent. It was not seeking territorial expansion. It was acting in self defense. But of course British historians cannot bear to admit that given Britain's huge losses in WWI......
PS. on a side note during the war after the British Royal family changed their name to the House of Windsor, Wilhelm II sarcastically commented that he was going to see a play - "the 3 merry wives of Saxe Coburg Gotha".
And yet, Russia and the world were worse off for losing him.
Austria Hungary was the culprit that lit the fuze and dragged the others into it over Serbia. Count von Hötzendorf as Austro-Hungarian Army Chief of Staff had demand war with Serbia many times prior to the assassination of the Arch Duke. Austria Hungary did not want a diplomatic solution with Serbia and they were too militarily weak to do conquer Serbia. They dragged the Germans in and then all the other alliance cards started to play.