The sinking of the civilian ship Lusitania by a German U-boat (submarine) which had US civilians on it angered them to becoming involved against the Germans.
The Germans had been slowly building up their military after the fall of the Weimar Republic; their invasion of Poland in 1939 was probably the most immediate cause of the world war.
The German invasion of Poland in 1939.
The attack on Pearl Harbor
The assassination of Archduke Franz Ferdinand.
World War I had 4 long-term causes and one immediate cause. The assassination of the Austro-Hungarian archduke was the immediate cause, the reason war was justified enough to actually begin. The other four are the MAIN causes of the war, Miliatariam, Alliances, Imperialism and Nationalism.
the cause
The immediate cause was Japan's attack on Pearl Harbor. This caused the US to declare war on Japan, which led to Germany and Italy declaring war on the US.
The Germans had been slowly building up their military after the fall of the Weimar Republic; their invasion of Poland in 1939 was probably the most immediate cause of the world war.
The German invasion of Poland in 1939.
The immediate cause of the first revolution in March 1917 was the disastrous impact of the First World War.
The attack on Pearl Harbor
The assassination of Archduke Franz Ferdinand.
That was the Archduke Franz Ferdinand.
World War I had 4 long-term causes and one immediate cause. The assassination of the Austro-Hungarian archduke was the immediate cause, the reason war was justified enough to actually begin. The other four are the MAIN causes of the war, Miliatariam, Alliances, Imperialism and Nationalism.
The immediate cause was Germany's invasion of Poland in 1939, but there were many underlying causes of the war, most which dated back to the conditions of the Treaty of Versailles after World War I.
The main cause of world war 1 was all of the alliances nations made. It was also because Archduke Franz Ferdinand was assassinated by a terrorist.
The German invasion of Poland on 1 September 1939