Answer:
The country was part of the Triple Alliance between 1883 and 1914 (initially Germany, Austria-Hungary and Russia, later also Italy and Romania) under which the Central Powers operated during World War I (WWI), but it changed sides in 1916 and became a member of the Entente. Romania hoped to make an advantageous entry into the war in order to realize long-held dreams of territorial expansion and national unity.
Step-by-step explanation:
put in your own words if it isn't just an anwser because it's not plagiarism proof :/