Question: The US and the country called Russia before the Russian Revolution became important members in a peace keeping organisation. When was Eritrea annexed by the largest troop contributor to that organisation?

full_context: Document 1: United Nations Population Fund: Contributions from governments and the private sector to UNFPA in 2014 exceeded $1 billion. The amount includes $477 million to the organization’s core resources and $529 million earmarked for specific programs and initiatives.
Document 2: Modern history: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
Document 3: Russian Revolution: The Russian Revolution was a pair of revolutions in Russia in 1917 which dismantled the Tsarist autocracy and led to the rise of the Soviet Union. The Russian Empire collapsed with the abdication of Emperor Nicholas II and the old regime was replaced by a provisional government during the first revolution of February 1917 (March in the Gregorian calendar; the older Julian calendar was in use in Russia at the time). Alongside it arose grassroots community assemblies (called 'soviets') which contended for authority. In the second revolution that October, the Provisional Government was toppled and all power was given to the soviets.
Document 4: United Nations Population Fund: In response, the EU decided to fill the gap left behind by the US under the Sandbaek report. According to its Annual Report for 2008, the UNFPA received its funding mainly from European Governments: Of the total income of M845.3 M, $118 was donated by the Netherlands, $67 M by Sweden, $62 M by Norway, $54 M by Denmark, $53 M by the UK, $52 M by Spain, $19 M by Luxembourg. The European Commission donated further $36 M. The most important non-European donor State was Japan ($36 M). The number of donors exceeded 180 in one year.
Document 5: List of members of the United Nations Security Council: As of July 2011, there are currently 193 members of the United Nations and five permanent members of the Security Council. The other ten seats are assigned amongst the remaining 188 members. As a result, many members have never been on the Security Council. The following list is a summary of all countries, currently 68 modern nations and three historical ones, that have never been a member of the United Nations Security Council. The three historical UN members listed are Tanganyika, Zanzibar, and the Federal Republic of Yugoslavia.
Document 6: Soviet Union: The Soviet Union suffered greatly in the war, losing around 27 million people. Approximately 2.8 million Soviet POWs died of starvation, mistreatment, or executions in just eight months of 1941 -- 42. During the war, the Soviet Union together with the United States, the United Kingdom and China were considered as the Big Four of Allied powers in World War II and later became the Four Policemen which was the foundation of the United Nations Security Council. It emerged as a superpower in the post-war period. Once denied diplomatic recognition by the Western world, the Soviet Union had official relations with practically every nation by the late 1940s. A member of the United Nations at its foundation in 1945, the Soviet Union became one of the five permanent members of the United Nations Security Council, which gave it the right to veto any of its resolutions.
Document 7: Eritrea: The Scottish traveler James Bruce reported in 1770 that Medri Bahri was a distinct political entity from Abyssinia, noting that the two territories were frequently in conflict. The Bahre-Nagassi ("Kings of the Sea") alternately fought with or against the Abyssinians and the neighbouring Muslim Adal Sultanate depending on the geopolitical circumstances. Medri Bahri was thus part of the Christian resistance against Imam Ahmad ibn Ibrahim al-Ghazi of Adal's forces, but later joined the Adalite states and the Ottoman Empire front against Abyssinia in 1572. That 16th century also marked the arrival of the Ottomans, who began making inroads in the Red Sea area.
Document 8: Great power: When World War II started in 1939, it divided the world into two alliances—the Allies (the United Kingdom and France at first in Europe, China in Asia since 1937, followed in 1941 by the Soviet Union, the United States); and the Axis powers consisting of Germany, Italy and Japan.[nb 1] During World War II, the United States, United Kingdom, and Soviet Union controlled Allied policy and emerged as the "Big Three". The Republic of China and the Big Three were referred as a "trusteeship of the powerful"  and were recognized as the Allied "Big Four" in Declaration by United Nations in 1942. These four countries were referred as the "Four Policemen" of the Allies and considered as the primary victors of World War II. The importance of France was acknowledged by their inclusion, along with the other four, in the group of countries allotted permanent seats in the United Nations Security Council.
Document 9: October Revolution: It followed and capitalized on the February Revolution of the same year, which overthrew the Tsarist autocracy and resulted in a provisional government after a transfer of power proclaimed by Grand Duke Michael, brother of Tsar Nicolas II, who declined to take power after the Tsar stepped down. During this time, urban workers began to organize into councils (soviets) wherein revolutionaries criticized the provisional government and its actions. After the Congress of Soviets, now the governing body, had its second session, it elected members of the Bolsheviks and other leftist groups such as the Left Socialist Revolutionaries to important positions within the new state of affairs. This immediately initiated the establishment of the Russian Socialist Federative Soviet Republic, the world's first self - proclaimed socialist state. On 17 July 1918, the Tsar and his family were executed.
Document 10: Eritrea: The creation of modern-day Eritrea is a result of the incorporation of independent, distinct kingdoms and sultanates (for example, Medri Bahri and the Sultanate of Aussa) eventually resulting in the formation of Italian Eritrea. In 1947 Eritrea became part of a federation with Ethiopia, the Federation of Ethiopia and Eritrea. Subsequent annexation into Ethiopia led to the Eritrean War of Independence, ending with Eritrean independence following a referendum in April 1993. Hostilities between Eritrea and Ethiopia persisted, leading to the Eritrean–Ethiopian War of 1998–2000 and further skirmishes with both Djibouti and Ethiopia.
Document 11: United Nations peacekeeping: As of 29 February 2016, 124 countries were contributing a total of 105,314 personnel in Peacekeeping Operations, with Ethiopia leading the tally (8,324), followed by India (7,695) and Bangladesh (7,525). In June 2013. Pakistan contributed the highest number overall with 8,186 personnel, followed by India (7,878), Bangladesh (7,799), Ethiopia (6,502), Rwanda (4,686), Nigeria (4,684), Nepal (4,495), Jordan (3,374), Ghana (2,859), and Egypt (2,750). As of 28 February 2015, 120 countries were contributing a total of 104,928 personnel in Peacekeeping Operations, with Bangladesh leading the tally (9446). As of March 2008, in addition to military and police personnel, 5,187 international civilian personnel, 2,031 UN Volunteers and 12,036 local civilian personnel worked in UN peacekeeping missions.
Document 12: Eritrea: Eritrea (/ˌɛrᵻˈtreɪ.ə/ or /ˌɛrᵻˈtriːə/;, officially the State of Eritrea, is a country in East Africa. With its capital at Asmara, it is bordered by Sudan in the west, Ethiopia in the south, and Djibouti in the southeast. The northeastern and eastern parts of Eritrea have an extensive coastline along the Red Sea. The nation has a total area of approximately 117,600 km2 (45,406 sq mi), and includes the Dahlak Archipelago and several of the Hanish Islands. Its name Eritrea is based on the Greek name for the Red Sea (Ἐρυθρὰ Θάλασσα Erythra Thalassa), which was first adopted for Italian Eritrea in 1890.
Document 13: United Nations Security Council: The Security Council consists of fifteen members. The great powers that were the victors of World War II -- the Soviet Union (now represented by the Russian Federation), the United Kingdom, France, the Republic of China (now represented by the People's Republic of China), and the United States -- serve as the body's five permanent members. These permanent members can veto any substantive Security Council resolution, including those on the admission of new member states or candidates for Secretary - General. The Security Council also has 10 non-permanent members, elected on a regional basis to serve two - year terms. The body's presidency rotates monthly among its members.
Document 14: Modern history: It is possible that around 62 million people died in the war; estimates vary greatly. About 60% of all casualties were civilians, who died as a result of disease, starvation, genocide (in particular, the Holocaust), and aerial bombing. The former Soviet Union and China suffered the most casualties. Estimates place deaths in the Soviet Union at around 23 million, while China suffered about 10 million. No country lost a greater portion of its population than Poland: approximately 5.6 million, or 16%, of its pre-war population of 34.8 million died.
Document 15: Eritrea: During the Middle Ages, the Eritrea region was known as Medri Bahri ("sea-land"). The name Eritrea is derived from the ancient Greek name for Red Sea (Ἐρυθρὰ Θάλασσα Erythra Thalassa, based on the adjective ἐρυθρός erythros "red"). It was first formally adopted in 1890, with the formation of Italian Eritrea (Colonia Eritrea). The territory became the Eritrea Governorate within Italian East Africa in 1936. Eritrea was annexed by Ethiopia in 1953 (nominally within a federation until 1962) and an Eritrean Liberation Front formed in 1960. Eritrea gained independence following the 1993 referendum, and the name of the new state was defined as State of Eritrea in the 1997 constitution.[citation needed]
ground_truth: 1953
sub_queries: what was russia called after the russian revolution Answer: the Soviet Union
the us and the Soviet Union became important members in Answer: the United Nations
largest troop contributor to the the United Nations peace keeping mission Answer: Ethiopia
When was Eritrea annexed by Ethiopia ? Answer: 1953