While Israel tries to defeat Hamas, they also have to worry about a much more dangerous paramilitary group on their northern border: Hezbollah.

The express purpose of Hezbollah, which formed 40 years ago, is also to eradicate Israel.

It would be a nightmare for Israel if Hezbollah swings in and backs Hamas up.

So where did Hezbollah form, why do they hate Israel, and what hand did Israel have in their creation?

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Catch up on our series about the Israel-Gaza conflict on YouTube: https://www.youtube.com/watch?v=aQ4x0gAzJx4