Tensions on Israel's northern border with Lebanon are heating up amid daily exchanges of rocket fire between Israeli Defense Forces and Hezbollah fighters. Fears are growing that Israel's war with Hamas in Gaza could spread to a broader regional conflict because Hezbollah is Iran's most powerful proxy force. On Ian Explains, Ian Bremmer unpacks Hezbollah's role within Lebanon, its history of fighting Israel in the south, and how Iran uses the militant group to further its interests in the region.