Related Link Historian Michael Oren rejects report Israel considered detonating the bomb in 1967

On the eve of the Arab-Israeli war, 50 years ago this week, Israeli officials raced to assemble an atomic device and developed a plan to detonate it atop a mountain in the Sinai Peninsula as a warning to Egyptian and other Arab forces, according to an interview with a key organizer of the effort that will be published Monday.

The secret contingency plan, called a “doomsday operation” by Itzhak Yaakov, the retired brigadier general who described it in the interview, would have been invoked if Israel feared it was going to lose the 1967 conflict. The demonstration blast, Israeli officials believed, would intimidate Egypt and surrounding Arab states — Syria, Iraq and Jordan — into backing off.

Israel won the war so quickly that the atomic device was never moved to Sinai. But Mr. Yaakov’s account, which sheds new light on a clash that shaped the contours of the modern Middle East conflict, reveals Israel’s early consideration of how it might use its nuclear arsenal to preserve itself.