Why did Portugal carry out pacification campaigns in Guinea-Bissau between 1913 and 1936?

Portugal carried out these pacification campaigns primarily to satisfy the requirement of "effective occupation" established by the 1884–85 Berlin Conference during the Scramble for Africa.12

Following the conference, European powers were required to demonstrate active control over their claimed territories to maintain international recognition of their sovereignty. Because the local Guinean population resisted, revolted, and mutinied against colonial encroachment, Portugal launched these brutal military campaigns—beginning with the efforts of Captain João Teixeira Pinto between 1913 and 1915—to suppress local opposition and solidify their administrative hold on the region. These campaigns, which continued through 1936, involved severe punitive measures and the use of mercenary forces to enforce colonial authority over the indigenous population, particularly coastal groups.12