Moore was handing over to the recuperated Pringle when Argentina invaded the Falkland Islands on 2 April 1982. He joined the task force planning team at Northwood before flying south to take command of land forces in theatre. His planning post was taken by Lieutenant General Richard Trant. Moore relieved Brigadier Julian Thompson as ground commander when he arrived shortly before the 5th Infantry Brigade, travelling ahead on to reach the islands on 30 May. Moore implemented the plans proposed by Thompson, with the British soldiers forced to march across the inhospitable islands in the absence of sufficient helicopters and against Argentine resistance. He accepted the surrender of the Argentinian commander, General de Brigada Mario Menéndez, in Port Stanley on 14 June 1982.