Why did the death of Franz Ferdinand lead to the war?
Now soon chaos in Europe ensues, many wars on many different fronts. Canada is obviously forced into the war, as they are still at the time very much connected to Britain. And when a poor military decision by Germany was made to sink the Lusitania, a passenger ship with many Americans on it, it made USA hostile to Germany, and soon they were involved in the war too. Technically it wasn’t a full “World” war like in world war 2, but still, involved many countries.