Yes but there were many other countries included aswell
Germany. Answer: yes Germany but Italy and Japan also declared war against Britain.
Germany and Japan
Germany's blitzkrieg against poland
Italy, Japan, and Germany
A declaration of war against Germany.
No
By Nazi Germany invading Poland, and Britain's ally, France joining Britain in declaring war against Germany, which in turn led Japan to declare war against Britain and France, which then escalated the war from a pan European to Global (eventually).
There was a deal between Germany and Britain that Germany will not attack France but Hitler break the deal and attacked France, hence Britain jumped into the world war 2.
Britain .
When Germany invaded Poland, Britain and France declared war against Germany.
e =mc^2
Britain and Germany were effected because they were at war against each other.