Maj Gen Yair Golan, Israel's deputy chief of staff, told international journalists on Wednesday that Hezbollah has developed capabilities that present "unprecedented" threats to Israel.
Israel estimates the group has over 100,000 rockets and missiles in its arsenal.
Golan says any future war will be "much harsher" than anything experienced in the past 20 years, and Israel will unleash all of its military capabilities.
He says "that could create devastating damage to Lebanon." Israel and Hezbollah fought a monthlong war in the summer of 2006 that ended in a stalemate.