Context_1 : Russian four square was started in the Soviet Union. Russian four square is a variation of the Russian game Квадрат (square). Context_2 : The Union Chapel, also known as the Union Street Chapel, Elim Free Church, Four Square Gospel Tabernacle or Elim Tabernacle of the Four Square Gospel, is a former chapel in the centre of Brighton, a constituent part of the city of Brighton and Hove, England. After three centuries of religious use by various congregations, the chapel—which had been Brighton's first Nonconformist place of worship—passed into secular use in 1988 when it was converted into a pub. It was redesigned in 1825, at the height of Brighton's Georgian building boom, by at least one of the members of the Wilds–Busby architectural partnership, Brighton's pre-eminent designers and builders of the era, but may retain some 17th-century parts. It has been listed at Grade II in view of its architectural importance. Context_3 : The Military Reaction Force, Military Reconnaissance Force or Mobile Reconnaissance Force (MRF) was a covert intelligence-gathering and counter-insurgency unit of the British Army active in Northern Ireland during the Troubles, a former member described it as a "legalised death squad". The unit was formed during the summer of 1971 and operated until late 1972 or early 1973. MRF teams operated in plain-clothes and civilian vehicles, equipped with pistols and submachine guns. They were tasked with tracking down and arresting, or killing, members of the Irish Republican Army (IRA). The MRF also ran double agents within the paramilitary groups and ran a number of front companies to gather intelligence. In October 1972, the Provisional IRA uncovered and attacked two of the MRF's front companies—a mobile laundry service and a massage parlour—which contributed to the unit's dissolution. Context_4 : The 2014 Enugu State Broadcasting Service Attack took place on June 5, 2014, when about 13 members of the Biafra Zionist Federation militant group attacked the Enugu State Broadcasting Service (ESBS) in an attempt to make a public announcement on radio and television declaring the sovereign state of Biafra. Context_5 : The Attack on the Four Square Laundry was a Provisional IRA ambush in the Twinbrook area of Belfast against a special British Military unit known as the Military Reaction Force. At least one undercover British soldier (Edward Stuart (20)) was killed, the IRA claimed they killed 5 undercover soldiers altogether. The attack took place on 2 October 1972. Context_6 : Four Square is a chain of supermarkets in New Zealand that was founded by John Heaton Barker. It has 280 stores throughout New Zealand, mostly in small towns. A number of Four Square supermarkets are also operated in Australia. Context_7 : The Al Furqan Brigades are a militant group that has been active throughout Egypt. The brigades attacked a container ship that was passing through the Suez Canal in September 2013. The group attacked a communications center in Maadi with RPGs in October 2013. Context_8 : A try square is a woodworking or a metalworking tool used for marking and measuring a piece of wood. The "square" refers to the tool's primary use of measuring the accuracy of a right angle (90 degrees); to "try" a surface is to check its straightness or correspondence to an adjoining surface. A piece of wood that is rectangular, flat, and has all edges (faces, sides, and ends) 90 degrees is called four square. A board is often milled four square in preparation for using it in building furniture. Context_9 : The personal attack rule was a corollary to the Federal Communication Commission's fairness doctrine that mandated response time for an individual or group attacked during "origination cablecasting" that focused on a controversial issue of public importance. While the fairness doctrine was repealed in 1987, the personal attack rule persisted until 2000, when it was first suspended and then abolished after an FCC comment period. Context_10 : The Action of 17 March 1917 was a German raid on British shipping in the Strait of Dover as well as the harbours of Ramsgate and Margate. Two flotillas of German torpedo boats set out from the coast of Flanders and split. One group attacked the British drifters and destroyers patrolling near Goodwin Sands, while the other attacked the towns of Ramsgate and Margate, shelling the towns and shipping in their harbors. While attempting to fight off the German squadron near Goodwin Sands, the destroyers HMS "Paragon" and HMS "Llewellyn" were torpedoed. "Paragon" was sunk and "Llewellyn" damaged before the Germans withdrew with no casualties. fact_1 : The Attack on the Four Square Laundry was a Provisional IRA ambush in the Twinbrook area of Belfast against a special British Military unit known as the Military Reaction Force. fact_2 :  The unit was formed during the summer of 1971 and operated until late 1972 or early 1973. Answer: summer of 1971
Output: When was the group attacked in the attack on the Four Square Laundry formed?