What kind of bomb that can destroy one country?

A thermonuclear bomb, also known as a hydrogen bomb, has the potential to cause widespread destruction and could theoretically devastate an entire country. These bombs use nuclear fusion to release an immense amount of energy, resulting in catastrophic blasts, intense heat, and radiation. The aftermath would include significant loss of life, long-term environmental damage, and destabilization of the region. However, the use of such weapons is heavily restricted by international treaties due to their destructive capabilities.