The essay analyses the case of the Vatican diplomatic position vis-à-vis the Anglo- Argentinian conflict for the Falkland Islands in 1982. This problem intersects the question of the Papal visit to the United Kingdom, scheduled right that year at the end of May. Her Majesty’s Government, led by Margaret Thatcher, fearing that John Paul II could be led to an undefined peace-loving position regardless of two UN Security Council Resolutions condemning Argentina’s occupation, made it clear that the conditioning of the Papal visit to a ceasefire in the Falkland Islands should be considered as an appeasement to Argentina’s unlawful acts. In order to avoid this and to allow the Pope to come to the UK, Ms. Thatcher accepted to deprive Papal visit of every possible political significance. On this Anglo-Vatican agreed line, John Paul II accepted to confirm his own visit. However, he secretly instructed Cardinal Casaroli, the Vatican Secretary of State, to arrange a meeting with Ms. Thatcher on the Falklands question. The secret Thatcher-Casaroli talk took place the very day of Wojtyla’s arrival to the UK, as soon as the Pope got ready to start his official pastoral visit. This work is based on primary British, American and Argentinian sources and on Cardinal Casaroli’s private papers filed in the Vatican archives.