By the time Israel’s advanced F-35 jet fighters swooped in to attack Iran’s nuclear facilities and military leadership, a lower-tech threat had already crossed the border and was in position to clear the way.

The retaliatory strikes came on Saturday, a day after Israel killed top Iranian military leaders and scientists and destroyed an aboveground nuclear enrichment plant near Natanz.

Iran on Friday night launched missiles and drones at Israel in a second response to airstrikes overnight that targeted nuclear sites and top commanders in the Islamic nation.