By the start of the century, the United States continued its interventionist attitude, which aimed to directly defend its interests in the region. This was officially articulated in Theodore Roosevelt's Big Stick Doctrine, which modified the old Monroe Doctrine, which had simply aimed to deter European intervention in the hemisphere. At the conclusion of the Spanish–American War the new government of Cuba and the United States signed the Platt Amendment in 1902, which authorized the United States to intervene in Cuban affairs when the United States deemed necessary. In Colombia, United States sought the concession of a territory in Panama to build a much anticipated canal across the isthmus. The Colombian government opposed this, but a Panamanian insurrection provided the United States with an opportunity. The United States backed Panamanian independence and the new nation granted the concession. These were not the only interventions carried out in the region by the United States. In the first decades of the twentieth century, there were several military incursions into Central America and the Caribbean, mostly in defense of commercial interests, which became known as the "Banana Wars."