What is Hezbollah and why did Israel recently escalate actions against them?

Hezbollah is one of the world's largest armed non-state military groups, possessing tens of thousands of trained soldiers and hundreds of thousands of missiles and rockets capable of threatening targets throughout the region. This significant threat led Israel to conduct massive attacks against the group, including a large explosion near Beirut's international airport that killed almost all of Hezbollah's top leaders. Israel followed these strikes with a full invasion aimed at further weakening the organization. This massive escalation, part of a fierce 40-year struggle between the two entities, has significant implications for regional stability and reflects broader tensions in the Middle East political landscape.