What is one bad decision made by Germany during world war 1?

One significant bad decision made by Germany during World War I was the implementation of unrestricted submarine warfare. This strategy aimed to cut off supplies to Allied nations but ultimately led to the sinking of civilian ships, including the Lusitania, which provoked international outrage. The decision contributed to the United States entering the war in 1917, tipping the balance against Germany and leading to its eventual defeat.