The highest ranks of the army and nobility turned against Nicholas II.
It was the highest ranking officers that told him he should stand down and nobility in the Duma who lead on refusing to follow the Tsar's orders.
Nicholas himself seemed to give up and accept he didn't have the ability to rule anymore.
His concern was more for his family than his nation and tsardom.
Nicholas' upbringing in the idea that all owed him absolute loyalty made him ignore genuine complaints and concerns and see them as disloyalty that must be punished.
The war illustrated that Nicholas was a weak ruler.
He was surrounded by ineffective ministers and hamstrung by the scandals surrounding his wife and Rasputin.
His regime was not strong enough to survive the rigours of war.