Final answer:
Sovereign immunity is the legal doctrine that protects a nation or state from being sued without its consent. It is enshrined in the Constitution through the Privileges or Immunities Clause, which also forbids states from discriminating against citizens of other states.
Step-by-step explanation:
The term that refers to the immunity a nation has against being sued is known as sovereign immunity. This principle makes states immune from lawsuits involving out-of-state citizens and foreigners not residing within the state borders. Sovereign immunity lays the foundation for a state's protection from legal action unless it consents to such action. The Constitution furthers this concept by instating the Privileges or Immunities Clause in Article IV, Section 2, which ensures states do not discriminate against citizens of other states, granting them the same rights and protections as their own citizens.
This idea of immunity can also be linked to the legal protections given by patents, trademarks, copyrights, and trade secret laws collectively known as intellectual property. Just like sovereign immunity protects a state from lawsuits, intellectual property laws protect the ownership of ideas and creations, highlighting a broader scope of immunity under the law.