During a crisis meeting headed by the Prime Minister Margaret Thatcher, the Chief of the Naval Staff, Admiral Sir Henry Leach, advised them that "Britain could and should send a task force if the islands are invaded". On 1 April, Leach sent orders to a Royal Navy force carrying out exercises in the Mediterranean to prepare to sail south.
The first mobile computers were heavy and ran from mains power. The first laptops, such as the Grid Compass, removed this requirement by incorporating batteries – and with the continued miniaturization of computing resources and advancements in portable battery life.
Following the invasion on 2 April, after an emergency meeting of the cabinet, approval was given to form a task force to retake the islands. This was backed in an emergency session of the House of Commons the next day.
On the evening of 3 April, the United Kingdom's United Nations ambassador Sir Anthony Parsons put a draft resolution to the United Nations Security Council.
The Chilean government also allowed the United Kingdom to requisition the refueling vessel RFA Tidepool, which Chile had recently purchased and which had arrived at Arica in Chile on 4 April. The ship left port soon afterwards, bound for Ascention Island through the Panama Canal and stopping at Curacao en route.
The first landings of SAS troops took place on 21 April, but—with the southern hemisphere autumn setting in—the weather was so bad that their landings and others made the next day were all withdrawn after two helicopters crashed in fog on Fortuna Glacier.
In preparation for Operation Beit ol-Moqaddas, the Iranians had launched numerous air raids against Iraq air bases, destroying 47 jets (including Iraq's brand new Mirage F-1 fighter jets from France); this gave the Iranians air superiority over the battlefield while allowing them to monitor Iraqi troop movements.
On 25 April, after resupplying the Argentine garrison in South Georgia, the submarine ARA Santa Fe was spotted on the surface by a Westland Wessex HAS Mk 3 helicopter from HMS Antrim, which attacked the Argentine submarine with depth charges.
The South Georgia force, Operation Paraquet, under the command of Major Guy Sheridan RM, consisted of Marines from 42 Commando, a troop of the Special Air Service (SAS) and Special Boat Service (SBS) troops who were intended to land as reconnaissance forces for an invasion by the Royal Marines.
On 29 April, Iran launched the offensive. 70,000 Revolutionary Guard and Basij members struck on several axes – Bostan, Susangerd, the west bank of the Karun River, and Ahvaz. The Basij launched human wave attacks, which were followed up by the regular army and Revolutionary Guard support along with tanks and helicopters.