WORLD HISTORY

Detailed explanation-1: -On September 3, 1939, in response to Hitler’s invasion of Poland, Britain and France, both allies of the overrun nation declare war on Germany.

Detailed explanation-2: -Hitler’s invasion of Poland in September 1939 drove Great Britain and France to declare war on Germany and World War II began. Over the next six years, the conflict would take more lives and destroy more land and property around the globe than any previous war.

Detailed explanation-3: -When Britain declared war on Germany on 3 September 1939 it did so for only one reason-Germany had invaded Poland, and Britain had guaranteed to support her ally, like it had supported Belgium in WW1. The diplomat and writer Sir Nicholas Henderson, himself a former ambassador to Poland, called it “a fatal guarantee".

Detailed explanation-4: -France and Britain responded to the invasion of Poland by declaring war on Germany on September 3, 1939. But they did not engage in a major battle with Germany until spring 1940, when the French, especially, found little success in halting the German advance in western Europe.

Detailed explanation-5: -The Causes of World War One Germany declared war on Russia in support of Austria and on France because of her alliance with Russia. Britain declared war on Germany in support of Belgium and France, and on Turkey because of her alliance with Germany.

Detailed explanation-6: -On 3 September 1939-two days after the German invasion of Poland-France declared war on Nazi Germany according to its defensive treaty with Poland, when France’s ultimatum to Germany, issued the previous day, expired at 17:00.