"管理国家的本领" can be translated into English as "the ability to govern a country" or "the capability of state administration".
"The ability to govern a country" directly conveys the idea of having the skills or competence to manage a nation's affairs.
"The capability of state administration" emphasizes the capacity or potential to perform the functions of governing a state.
Both translations are appropriate and can be used depending on the context and the desired emphasis.