Now 50, Harel is ready to rejoin the army to fight the same group if shelling along Israel’s northern border turns into a full-blown war with Iran’s most powerful regional proxy. This time Israeli forces would face some of the most challenging fighting conditions imaginable, he said.

"There are booby traps everywhere," he told Reuters. "People are popping up from tunnels. You have to be constantly on alert otherwise you will be dead."

Harel lives in Haifa, Israel’s third biggest city, well within range of Hezbollah’s weapons. Haifa’s mayor recently urged residents to stockpile food and medicine because of the growing risk of all-out war.

Israel and Hezbollah have been engaged in escalating daily cross-border strikes over the past six months - in parallel with the war in Gaza - and their increasing range and sophistication has spurred fears of a wider regional conflict.

Hezbollah has amassed a formidable arsenal since 2006.