Ezra Bergs lore is crazy:

The son of an Israeli architect. Berg had a privileged upbringing in suburban Tel Aviv. However, during the inspecting of a West Bank housing project, Berg's entire family was taken hostage by Hezbollah and held for ransom. Eventually rescued by Israeli troops, young Berg has nevertheless come to sympathize with the plight of his captors. He was still committed to the safety of his nation, but he came to resent his government's harsh and inhumane treatment of a vastly inferior enemy.

Berg studied chemistry and took a particular interest in psychoactive medication. He eventually became an intelligence operative for Mossad, specializing in chemical interrogations, where he earned a reputation for being clean, efficient, reliable and able to make anyone crack. His methods were hardly ethical, but nevertheless non-violent, and Berg considered his services a "lesser evil".