Who is Yahya Sinwar, the new leader of Hamas?

The new leader of the militant group Hamas has a brutal reputation and a deep understanding of Israel. Yahya Sinwar rose through the ranks to become head of a wing charged with eliminating spies for Israel. He spent decades in Israeli jails, where he learned Hebrew and studied Israeli history. He was released in an exchange for an Israeli soldier and eventually rose to become Hamas’ leader in Gaza. Sinwar is considered the mastermind behind the deadly Oct. 7 attack on Israel that sparked the current war in Gaza. He has been in hiding since then and is not expected to be able to run Hamas on a day-to-day basis.