Nostra Aetate runs to about sixteen hundred words and took three years and four drafts to produce. John XXIII asked Cardinal Augustin Bea in 1960 to prepare a statement on the Jews, after a meeting with the historian Jules Isaac, whose work had traced the teaching of contempt through Christian preaching and catechesis. The first draft was a decree on the Jews alone. Political pressure from Arab states, which read any Catholic statement on Jews as a statement about Israel, and objections from bishops in Muslim majority countries, pushed the text through successive revisions until it became a declaration on non-Christian religions generally, with the Jewish section as its fourth part.
The final text says that the Church rejects nothing that is true and holy in other religions. It speaks of Hindus contemplating the divine mystery, of Buddhists teaching a way of liberation, and of Muslims who adore the one God, living and subsisting, merciful and almighty, and it urges that the quarrels and hostilities of the past be forgotten.
The fourth section is the one that changed practice. It states that the Church draws sustenance from the root of the good olive tree onto which the Gentiles have been grafted, that what was done in the passion cannot be charged against all the Jews then alive nor against the Jews of today, that they are not to be presented as rejected or accursed, and that the Church decries antisemitism at any time and from any source.