First US publication, first paperback publication (No additional printings noted).  Pages toned. Owner's and book store marks in the front matter. Spine creased, with laminated peeling along the crease. reinforced with non-yellowing tape by the previous owner. Edge wear.

The longest six minutes in history

Russian missiles were hurling toward the coast of England; British warheads were in flight to the enemy targets. The life of mankind was ticking away second by second...

Novel about men brought to face the fact that their work has made nuclear catastrophe possible.