What is the meaning of Sovereign?

Sovereign refers to a debt security issued by a government other than the United States. It is often believed that the issuing government via its treasury will fully back the payment of interest and principal in a timely manner. Sometimes, that backing is insufficient and a default occurs. At times of default, there are distinctions. Sometimes, there is a political upheaval and the new regime repudiates the former's obligations. At other times, there can be a lack of specified reserves to honor the obligations but a workout or restructuring of the payment schedule is agreed, bilaterally.