<human>:  How did guerrilla warfare originate?
<bot>: Guerrilla warfare was first used by the Irish Republican Army during the Irish War of Independence. The IRA used guerilla warfare tactics to fight against the British forces. Guerrilla warfare is a strategy that involves small groups of fighters fighting a larger force. The goal of guerilla warfare is to wear down the enemy through constant attacks and raids, which disrupts the enemy's ability to operate effectively.