Well, if you look more deeply into history you will see a fair number of such examples. Boycotting Germany during WWI caused a shortage of raw materials and led to food shortages already in 1915. This, in turn, caused a wave of food-related riots across the country in summer 1916, weakened German economy and caused the November Revolution of 1918.
It should not be forgotten that Allied victory and the Treaty of Versailles were brought about not only by military means. And by the way, the role of propaganda at that time (“black and white”) was no less than today.