Answer:
A strong naval blockade
Step-by-step explanation:
During world war 1 Germany wanted to starve Britain of supplies so they began an unrestricted submarine war sinking any ship that went towards the British mainland. In the beginning, it was bearable but after a few years, Germany started to suffer due to low rations and no import of materials needed for the war. At the end of the war, food was scarce, equipment was hard to produce and there was no money to fund the war effort.