Adolf Hitler.
If this question is in reference to World War II, most countries declared war on Germany because Germany declared war on them.
The prime minister of Britain declared war in Germany. The world war 2 started by Germany in a unprovoked attack on poland.
Australia declared war on Germany as well.
In World War 2?
France entered WWII because of a defensive pact woth Poland. Because Germany declared War on Poland, France declared war on Germany. If Germany had declared war on France first, then Poland would have declared war on germany. -Feewet
After the Japanese bombed Pearl Harbor and the U.S. declared war on them, Germany declared war on the U.S.
Poland never declared war on Germany. Germany declared war on Poland and invaded it in 1939. The United Kingdom warned Germany to withdraw its troops from Poland but Germany gave no heed. This forced the United Kingdom and France to declare war against Germany and the Second World War had begun.
World War 2 started on 1 September 1939 when Germany invaded Poland. Britain and France then declared war on Germany on 3 September 1939.
The US declared war on Germany, hour after Germany declared war on the US on December 11, 1941.
Germany declared war on the US after Pearl Harbour.
The US declared war on Germany on Dec 11th 1941, (two days after Germany declared war on the US). Everything since that date to the present is after.
europe