Vietnam is 2.8 times larger than Eritrea.
Area: 117,600 km2 World Factbook
Population: 6,380,803 (July 2014) World Factbook
Eritrea, officially the State of Eritrea, is a country in the Horn of Africa. Eritrea is the Italian form of the Greek name Ἐρυθραία, meaning "red [land]". With its capital at Asmara, it is bordered by Sudan to the west, Ethiopia in the south, and Djibouti in the east. Wikipedia
Area: 331,210 km2 World Factbook
Population: 93,421,835 (July 2014) World Factbook
Vietnam, officially the Socialist Republic of Vietnam, is the easternmost country on the Indochina Peninsula in Southeast Asia. With an estimated 90.0 million inhabitants as of 2013, it is the world's 13th-most-populous country, and the eighth-most-populous Asian country. Wikipedia