ARA General Belgrano (C-4) was an Argentine Navy light cruiser in service from 1951 until 1982. Originally commissioned by the U.S. Navy as , she saw action in the Pacific theatre of World War II before being sold to Argentina. The vessel was the second to have been named after the Argentine founding father Manuel Belgrano (1770–1820). The first vessel was a 7,069-ton armoured cruiser completed in 1896.

She was sunk on 2 May 1982 during the Falklands War by the Royal Navy submarine with the loss of 323 lives. Losses from General Belgrano totalled just under half of Argentine military deaths in the war.

She was the first ship to have been sunk during military operations by a nuclear-powered submarine and the second sunk in action by any type of submarine since World War II.

Early career

thumb|left|Phoenix at [[Pearl Harbor in 1941]]

The warship was built as , the sixth ship of the design, in Camden, New Jersey, by the New York Shipbuilding Corporation starting in 1935, and launched in March 1938. She survived the Japanese attack on Pearl Harbor in 1941 undamaged, and went on to earn nine battle stars for World War II service. At the end of the war, she was placed in reserve at Philadelphia on 28 February 1946, decommissioned on 3 July that year and remained laid up at Philadelphia.

Phoenix was sold to Argentina in October 1951 and renamed 17 de Octubre after the "Loyalty day", an important symbolic date for the political party of president Juan Perón. Sold with her was another of her class, , renamed , which was withdrawn in 1977.

17 de Octubre was one of the main naval units that joined the 1955 coup which overthrew Perón, and was afterwards renamed General Belgrano after Manuel Belgrano, a lawyer who had founded the Escuela de Náutica (School of Navigation) in 1799 and with the rank of general fought for Argentine independence from 1811 to 1819. General Belgrano accidentally rammed her sister ship Nueve de Julio on exercises in 1956, causing damage to both.

Sinking

thumb|right|upright=1.5|Deployment of naval forces on 1–2 May 1982 in the South Atlantic

On 12 April 1982, following the 1982 invasion of the Falkland Islands, the United Kingdom declared a Maritime Exclusion Zone (MEZ) around the Falkland Islands within which any Argentine warship or naval auxiliary entering the MEZ might be attacked by British forces. On 23 April, the British Government clarified in a message that was passed via the Swiss Embassy in Buenos Aires to the Argentine government that any Argentine ship or aircraft that was considered to pose a threat to British forces would be attacked.

On 30 April this was upgraded to the total exclusion zone, within which any sea vessel or aircraft from any country entering the zone might be fired upon without further warning. The zone was stated to be "...without prejudice to the right of the United Kingdom to take whatever additional measures may be needed in exercise of its right of self-defence, under Article 51 of the United Nations Charter." The concept of a total exclusion zone was a novelty in maritime law; the Law of the Sea Convention had no provision for such an instrument. Regardless of the uncertainty of the zone's legal status, it was widely respected by the shipping of neutral nations.

The Argentine military junta began to reinforce the islands in late April when it was realised that the British Task Force was heading south. As part of these movements, Argentine naval units were ordered to take positions around the islands. Two Task Groups designated 79.1, which included the aircraft carrier plus two Type 42 destroyers, and 79.2, which included three Exocet missile-armed s, sailed to the north. General Belgrano had left Ushuaia in Tierra del Fuego on 26 April. Two destroyers, ARA Piedra Buena and ARA Hipólito Bouchard (also ex-USN vessels) were detached from Task Group 79.2 and together with the tanker YPF Puerto Rosales, joined General Belgrano to form Task Group 79.3.

By 29 April, the ships were patrolling the Burdwood Bank, south of the islands. On 30 April, General Belgrano was detected by the British nuclear-powered hunter-killer submarine . The submarine approached over the following day. On 1 May 1982, Admiral Juan Lombardo ordered all Argentine naval units to seek out the British task force around the Falklands and launch a "massive attack" the following day. General Belgrano, which was outside and to the south-west of the exclusion zone, was ordered south-east.

Lombardo's signal was intercepted by British Intelligence. As a result, Prime Minister Margaret Thatcher and her War Cabinet, meeting at Chequers the following day, agreed to a request from Admiral Terence Lewin, the Chief of the Defence Staff, to alter the rules of engagement and allow an attack on General Belgrano outside the exclusion zone. Although the group was outside the British-declared total exclusion zone of 370 km (200 nautical miles) radius from the islands, the British decided that it was a threat. After consultation at Cabinet level, Thatcher agreed that Commander Chris Wreford-Brown should attack General Belgrano.

At 14:57 (Falkland Islands Time) on 2 May, Conqueror fired three 21-inch Mk 8 mod 4 torpedoes (conventional, non-guided, torpedoes in service from 1927), each with an 805-pound (363 kg) Torpex warhead. While Conqueror was also equipped with the newer Mark 24 Tigerfish homing torpedo, there were doubts about its reliability. Initial reports from Argentina claimed that Conqueror fired two Tigerfish torpedoes on General Belgrano. Two of the three torpedoes hit General Belgrano. According to the Argentine government, General Belgrano position was .

One of the torpedoes struck aft of the bow, outside the area protected by either the ship's side armour or the internal anti-torpedo bulge. This blew off the ship's bow, but the internal torpedo bulkheads held and the forward powder magazine for the 40 mm gun did not detonate. It is believed that none of the ship's company were in that part of the ship at the time of the explosion.

The second torpedo struck about three-quarters of the way along the ship, just outside the rear limit of the side armour plating. The torpedo punched through the side of the ship before exploding in the aft machine room. The explosion tore upward through two messes and a relaxation area called "the Soda Fountain" before finally ripping a hole in the main deck. Later reports put the number of deaths in the area around the explosion at 275 men. After the explosion, the ship rapidly filled with smoke. The explosion also damaged General Belgrano electrical power system, preventing her from putting out a radio distress call. Though the forward bulkheads held, water was rushing in through the hole created by the second torpedo and could not be pumped out because of the electrical power failure. In addition, although the ship should have been "at action stations", she was sailing with the water-tight doors open.

The ship began to list to port and to sink towards the bow. Twenty minutes after the attack, at 16:24, Captain Bonzo ordered the crew to abandon ship. Inflatable life rafts were deployed, and the evacuation began without panic.

The two escort ships were unaware of what was happening to General Belgrano, as they were out of touch with her in the gloom and had not seen the distress rockets or lamp signals.

Following the loss of General Belgrano, the Argentine fleet returned to its bases and played no major role in the rest of the conflict. British nuclear submarines continued to operate in the sea areas between Argentina and the Falkland Islands, gathering intelligence, providing early warning of air raids and effectively imposing sea denial. With the withdrawal of the aircraft carrier ARA Veinticinco de Mayo, all Argentine aircraft had to operate from land bases at the limit of their range. The minimal role of the Navy in the rest of the campaign led to a considerable loss of credibility and influence within the Junta.

Controversy over the sinking

The legality of the sinking of General Belgrano has been disputed due to disagreement on the exact nature of the Maritime Exclusion Zone (MEZ) and whether General Belgrano had been returning to port at the time of the sinking. Through a message passed via the Swiss Embassy in Buenos Aires to the Argentine government nine days before the sinking, the UK made clear that it no longer considered the 200 mile exclusion zone as the limit of its military action. On 1 May 1982, Admiral Juan Lombardo ordered all Argentine naval units to seek out the British task force around the Falklands and launch a "massive attack" the following day. Captain Bonzo stated that any suggestion that HMS Conqueror actions were a "betrayal" was utterly wrong; rather, the submarine carried out its duties according to the accepted rules of war.

The sinking became a cause célèbre for British anti-war campaigners such as Labour MP Tam Dalyell. Early reports suggested that more than 1,000 Argentine sailors might have been killed in the sinking; it was around a third of that number.

The sinking occurred 14 hours after President of Peru Fernando Belaúnde proposed a comprehensive peace plan and called for regional unity, although Margaret Thatcher and diplomats in London did not see this document until after the sinking of General Belgrano. Diplomatic efforts to that point had failed completely. After the sinking, Argentina rejected the plan but the UK indicated its acceptance on 5 May. The news was subsequently dominated by military action and the British continued to offer ceasefire terms until 1 June that were rejected by the Junta.

Argentine response

On 3 May 1982, Argentina's Chancellery released a statement in the name of the Argentinian government that read:

Neither the United Kingdom nor Argentina declared war during the conflict. Combat was confined to the Falkland Islands, South Georgia, and the surrounding area. General Belgrano was sunk outside the total exclusion zone around the Falklands, delimited by the UK. Through a message passed via the Swiss Embassy in Buenos Aires to the Argentine government on 23 April, the UK had made clear that it no longer considered the 200-mile (370 km) exclusion zone as the limit of its military action. The message read: