Factors in order of importance:
1) The failure of the Schlieffen Plan in 1914 meant Germany had to fight on two fronts.
This is very important as it stretched supplies of men and supplies to keep them going. This failure disheartened the country and destroyed general faith in Moltke who changed the plan. The victory over Germany early on for the allies livened up their spirits and made them the side with better morale.
2) The USA joined the war in April 1917. This gave the allies more economic and industrial strength.
The Germans were the reason for the USA entering the war creating a big weakness for them. They had enraged a large power which could so easily have been their key to win the war. A desperate error made by German generals I think: the war could be totally different in outcome.
3) The Spring Offensive of 1918 had failed. The Allied counter-attack pushed the Germans back.
The failure of this last attempt to knock the allies out of the war was a failure due to the allied counter attack, this disheartened the troops and those at home. Many believed the war was lost when the Spring offensive was lost.
4) The Royal Navy had defeated German U-boat attempts to halt supplies by using a convoy system.
The U-boat convoy system was stopped successfully by the Royal Navy in 1917 and sent a shock wave to the German generals that the war at sea to get the British to surrender wasn’t going to be easy! This affected other plans and made the Germans insecure about challenging Britain.
5) The Allied naval blockade of German ports left Germany starved of raw materials and food from abroad.
The blockades of Th German ports and the neutral port (from which Germany tried to receive raw materials) enraged the people at home and made the war harder to cope with. This is an important reason form the collapse of the German campaign. Germany needed their people to keep alive the patriotism, they wouldn’t have the energy if they had no food (!)
6) The civilians in Germany lost their fighting spirit , and were near starvation riots and revolution in 1918
The people of Germany had spent many years suffering at the hands of war ever since the Schliffen plan failed many had lost faith already for example…
” I knew it was over when I heard. The allied forces were too strong, but they’d carry on fighting to prove they could do it.” Dana Molkeret, 1920 fighting made Generals think about how they felt.
7) British and French supplies of food were good, unlike those of the Germans.
This is a factor that affects the mental aspect of war although it was physically raining for the Germans. They were worse off than ever before.
8) The war went on too long for Germany
This factor means that the war went on so long that so many problems could and did occur for Germany. All resources were drained, money was all put into the war effort, they dug themselves into debt and ailing battles and couldn’t get out.
9) Germanys allies, the Austro-Hungarians had seen their empire collapse. Austria surrendered on 3 November 1917
Germany had ‘lost their right arm’ when Austria left the war they lost their financial input and man power; supplies and technology.
10) Germanys allies, Bulgaria and Turkey surrendered in September and October 1918
yet another blow to Germanys finacial; man power; supplies and technology.
11) The British and French armies used 800 tanks in their counter attack in 1918 , The German tank was still in development stage AND The tank made trench warfare out of date.
I have put these three factors together as they all are incorporating 1 factor in three parts. In the counter attack against Germany tanks- a creation German were still developing which caused them to become behind technologically- were more effective at gaining land etc. Much more productive than Trench warfare.