Ancient borders should not be used directly to determine modern territorial sovereignty. Sovereignty and border issues in modern international law are usually considered comprehensively based on historical background, international treaties, national self-determination, actual control and other factors. Although historical factors can affect the demarcation of modern borders in some cases, international relations tend to rely on the current effective legal and political framework to resolve disputes. The United Nations Charter and various international treaties are the basis for contemporary handling of territorial disputes, not the definition of ancient borders. Although history is important, it usually needs to be considered together with other factors to reach a fair and sustainable solution.