Explained: The Hezbollah Threat At Israel-Lebanon Border

Israel's northern border with Lebanon is often tense, the legacy of past conflicts. But as Israel readies to invade Gaza, its army faces the threat of a two-front war. Repeated fire in recent days has claimed lives on both sides of the UN-patrolled border between Lebanon and Israel, which remain technically at war.

If Israel does invade the Palestinian enclave of Gaza in its war on Hamas, Lebanon's Iran-backed Hezbollah movement has warned it may escalate its military involvement.