It cost Israel more than $1bn to activate its defence systems that intercepted Iran’s massive drone and missile attack overnight, according to a former financial adviser to Israel’s military.

“The defence tonight was on the order of 4-5bn shekels [$1-1.3bn] per night,” estimated Brigadier General Reem Aminoach in an interview with Ynet news.

“If we’re talking about ballistic missiles that need to be brought down with an Arrow system, cruise missiles that need to be brought down with other missiles, and UAVs [unmanned aerial vehicles], which we actually bring down mainly with fighter jets,” he said.

“Then add up the costs - $3.5m for an Arrow missile, $1m for a David’s Sling, such and such costs for jets. An order of magnitude of 4-5bn shekels.”