What drives Hezbollah's political behaviour? For three decades we believed that the impetus of establishing an Islamic state in Lebanon was its main goal. This book disagrees. Drawn from over fifteen years of research, it traces Hezbollah's political trajectory, or socialisation process, from its birth in 1982 to 2017. It identifies the religio-political identity and doctrine that inspire Hezbollah and the politico-strategic goals that motivate it. It argues that war-making with Israel has driven Hezbollah's socialisation in Lebanon and the region, transforming the Islamist movement from a loose organization into one of the world's most powerful and sophisticated armed political movements.