France. Germany and France share a border.
Austria, Czechoslovakia, and Poland (The U.K. declared war 3 days later, after Hitler ignored a British ultimatum to leave).
Poland
The first country was Poland. On 1 September 1939, German forces invaded Poland so on 3 September 1939, Britain and France declared war on Germany.
Britain declared war on Germany because Germany attacked Belgium in order to strategically invade France. Britain vowed to protect Belgium, so Britain joined World War I.
When Britain and France declared war on Germany because Germany sent a million troops to invade Poland.
Germany invading Poland and the us joined the fight when Japan bombed Pearl Harbor.
Germany did not invade Britain in WW2. Britain has not been invaded for a thousand years.
Russia got to Germany way before the U.S or Great Britain.
It was the invasion of Poland that really got things moving and i believe when that happened, thats when Great Britain declared war.
Great Britain and France declared war on Germany, when Germany invaded Poland - so began the second World War in Europe.
september 1939