On 4 May, two days after the sinking of General Belgrano, the British lost the Type 42 destroyer HMS Sheffield to fire following an Exocet missile strike from the Argentine 2nd Naval Air Fighter/Attack Squadron.
On 14 May the SAS carried out a raid on Pebble Island on the Falklands, where the Argentine Navy had taken over a grass airstrip for FMA IA 58 Pucará light ground-attack aircraft and Beechcraft T-34 Mentors, which resulted in the destruction of several aircraft.
South Korea's first Internet system, the System Development Network (SDN) began operation on 15 May 1982. SDN was connected to the rest of the world in August 1983 using UUCP (Unixto-Unix-Copy); connected to CSNET in December 1984; and formally connected to the U.S. Internet in 1990.
A SAS reconnaissance team was dispatched to carry out preparations for a seaborne infiltration. A Westland Sea King helicopter carrying the assigned team took off from HMS Invincible on the night of 17 May, but bad weather forced it to land 50 miles (80 km) from its target and the mission was aborted.
The tempo of operations increased throughout the first half of May as the United Nations' attempts to mediate a peace were rejected by the Argentinians. The final British negotiating position was presented to Argentina by UN Secretary General Pérez de Cuéllar on 18 May 1982.
On 20 May 1982, Robert Muldoon announced that New Zealand would make HMNZS Canterbury, a Leander-class frigate, available for use where the British thought fit to release a Royal Navy vessel for the Falklands. The New Zealand government expelled the Argentinian ambassador following the invasion. The Prime Minister, Robert Muldoon, was in London when the war broke out.
During the night of 21 May, the British Amphibious Task Group under the command of Commodore Michael Clapp (Commodore, Amphibious Warfare – COMAW) mounted Operation Sutton, the amphibious landing on beaches around San Carlos Water, on the northwestern coast of East Falkland facing onto Falkland Sound.
In the early morning hours of 23 May 1982, the Iranians began the drive towards Khorramshahr across the Karun River. This part of Operation Beit ol-Moqaddas was spearheaded by the 77th Khorasan division with tanks along with the Revolutionary Guard and Basij.
The Iranians hit the Iraqis with destructive air strikes and massive artillery barrages, crossed the Karun River, captured bridgeheads, and launched human wave attacks towards the city. Saddam's defensive barricade collapsed; in less than 48 hours of fighting, the city fell and 19,000 Iraqis surrendered to the Iranians.
From early on 27 May until 28 May, 2 Para, (approximately 500 men) with naval gunfire support from HMS Arrow and artillery support from 8 Commando Battery, Royal Artillery, approached and attacked Darwin and Goose Green, which was held by the Argentine 12th Infantry Regiment.