When, after war service, he eventually sat at the editor's desk he began a transformation which made the paper a reflection of his own ideals of liberalism, internationalism and tolerance. He assembled a team of the most talented and intellectually brilliant writers imaginable Arthur Koestler, Fritz Schumacher, John Gale, Patrick O'Donovan, Kenneth Tynan, Gavin Young, Nora Beloff, Anthony Sampson, Colin Legum, William Clark, Alastair Buchan, Peter Benenson, among many others. Astor was interested in ideas and his writers were fecund. Koestler led the way on the abolition of capital punishment, Schumaker pioneeed intermediate technology for the Third World (Small is Beautiful) and a Benenson article led to the creation of Amnesty International.
David Astor's greatest interest was in foreign affairs. In 1956 The Observer took a strong line against Anthony Eden's Suez adventure, describing it as foolish and wicked in a leading article. Subscriptions were cancelled and advertisers withdrew their bookings.
Although subsequent revelations justified what Astor had said, the paper never recovered and its place as the leading Sunday newspaper of ideas was eventually taken by the Sunday Times.
Astor retired as editor in 1975 but retained his connection until the paper was sold to Tiny Rowland's Lonrho. No doubt it was a great relief to him that it later became part of the Guardian Group.