The former Secretary-General Javier Pérez de Cuéllar, who has died aged 100, was responsible for a series of diplomatic breakthroughs that were “perhaps without parallel, in the history of the UN.”

That’s according to his most senior aide, Chef de Cabinet Virendra Dayal, in an interview on Thursday by phone from his home in Delhi. Mr. Dayal praised the “inherent decency and integrity” of the former UN chief, who served two terms that saw the end of the Cold War, telling UN News’s Matt Wells that Mr. Pérez de Cuéllar played a key role in the transition, “in an absolutely masterly manner.”