The text describes "the madness of war" and in it, the Queen would have inspired her "brave country" to hold a united front.
"Now this madness of war is once more spreading through the world and our brave country must again prepare itself to survive against great odds," read the speech, which was written by Whitehall officials as part of a war preparation exercise.
CLICK ON PHOTO FOR GALLERY
The text was drafted at the peak of the Cold War, which lasted from 1947 to 1991, when Britain and its ally, the US, were facing genuine threats of nuclear attacks from the Soviet Union.
While the speech was never delivered, it offers a picture of the unsettling times the reigning monarch and her nation lived through, and how close the world came to facing a third world war.
The Queen's speech would have recalled the time that the young royal and her sister Princess Margaret huddled around the nursery wireless set listening to their father King George VI's "inspiring words on that fateful day" in 1939, when Britain declared war on Nazi Germany.
"Not for a single moment did I imagine that this solemn and awful duty would one day fall to me," added the script. The monarch would also have reflected on the "sad century" the nation had witnessed, having already experienced two world wars.
The speech was filled with emotion as it described how the Queen could empathise with the families before her, who all knew of a son, daughter, husband or brother that had left their side to serve the country.
"My beloved son Andrew is at this moment in action with his unit," read the text. "We pray continually for his safety and for the safety of all servicemen and women at home and overseas."
Her message and solution was therefore "simple", the Queen would have concluded. She urged her fellow countrymen to help and comfort each other and put on a united front, to triumph over this "new evil".
"If families remain united and resolute, giving shelter to those living alone and unprotected, our country's will to survive cannot be broken," the address said.
The speech, which fortunately the Queen never had to deliver, was originally due to be broadcast at noon on Friday 4 March, 1983.
It was released from secret files on Thursday by the National Archives, under the new 20-year rule where hundreds of government records from that year have been made public.
Buckingham Palace could not confirm whether the Queen had ever seen the speech, saying that the reigning monarch had received many government papers during her time.