After world war i, which country emerged as a dominant world power?

After World War I, the United States of America emerged as a dominant world power.

Explanation:

The United States became independent from Great Britain at the end of the 18th century, but it would be after the Civil War when its real industrial and immigration boom would begin. American industrial growth was such that before the end of the century its economy already produced more than the British. However, it was not yet considered one of the great powers, as they had little military and political weight. It was during the government of Theodore Roosevelt when this changed, and after the victory along with the Triple Entente in the First World War it was recognized as the new hegemonic power of the world.