He heads Hezbollah's External Security Organization (ESO), also known as Unit 910, which is responsible for planning and executing terrorist activities outside Lebanon.

He became known to intelligence officials after he was caught on an intercepted communication celebrating the AMIA bombing, in which 85 people were killed, in Argentina.

For many years he was Mugniyeh's deputy, directing the 1996 Khobar Towers bombing, in which 19 U.S. soldiers were killed, and attacks against the IDF during the Second Lebanon War.

[2][3][4] After Badreddine was indicted by the Special Tribunal for Lebanon for charges related to the assassination of Rafic Hariri in 2011, Hamiyah reportedly assumed command of Hezbollah's military operations.

[6] The U.S. State Department added him to its Rewards for Justice Program (RFJ) on October 10, 2017, offering $7 million for information leading to his arrest.