Hizballah plans to dispatch scores of terrorists into Israel while striking civilian communities with missiles in a future war that could last months, a senior Israeli source told reporters.

The terrorist organization's confidence grew, based on experience gained from its military intervention in Syria on behalf of dictator Bashar al-Assad. That, the Israeli military official believes, has the group considering going on the offensive. A pre-emptive Israeli ground operation could prevent such incursions.

"The battlegrounds of Syria have enabled Hezbollah to upgrade its capabilities. Hezbollah plans to send many combatants into Israeli territory near the border and seize it," said the source, adding that Israel was forced to make "dramatic changes" to its border-defense assessments as a result.

Such a conflict is not considered imminent, as Hizballah still has significant forces in Syria fighting for Assad and against the Islamic State.

According to the officer, there are no known tunnels leading into Israel from Lebanon; however, the terrorist organization has constructed a vast and sophisticated network of tunnels and underground bunkers in southern Lebanon. With Iranian help, Hizballah taught Hamas how to build their own tunnel network in the Gaza Strip.

Hizballah is believed to have tens of thousands of rockets with greater sophistication and power than those Hamas fired into Israel from Gaza.

To eliminate any threat, Israeli officials have said they'll have to launch a ground attack deep into Lebanon. The collateral damage would be significant, the source acknowledged.

Fighting in Syria taught Hizballah about battlefield command and control of its ground forces and intelligence. Israel doesn't expect immediate hostilities, the source said, but is preparing for the possibility and remains confident that "There is no challenge in Lebanon that the IDF (Israel Defense Forces) cannot overcome. There is no village in Lebanon in which the IDF can't overwhelm Hezbollah."