Which country was part of the war but never signed the Treaty of Versailles? Germany, the US, France or Britian?

http://en.wikipedia.org/wiki/Treaty_of_Versailles#United_States_rejects_Treaty

The country that was part of the war but never signed the Treaty of Versailles is the United States. To find this answer, we first need to understand what the Treaty of Versailles is. The Treaty of Versailles was a peace agreement signed in 1919 that officially ended World War I and laid out the terms for peace. It was primarily negotiated between the Allied powers (including the United States, France, and Britain) and Germany, which was considered the main aggressor in the war.

However, despite being part of the war effort, the United States chose not to sign the Treaty of Versailles. This decision was due to a combination of factors, including disagreements over the treaty's terms and concerns about the growing isolationist sentiment within the U.S. Congress. As a result, the United States negotiated its separate peace agreement with Germany known as the Treaty of Berlin in 1921. Therefore, the correct answer to your question is the United States.