As modern international law has "Rule of occupation" (rule under which the county that discovered a land first has sovereignty) as one of its features, "undeveloped country" was automatically deemed as "terra nullius," and, therefore, colonies could be established freely (Kobayashi 2002).
近代国際法は「先占の原則」（早期発見国が領有権を有する原理）を特徴の一つとして持っていたので、「未開国」は自動的に「無主の地」とされ、そこに植民地を自由に設定できるということになる（小林2002）。