One philosophy of nuclear targeting. Countervalue targeting is the practice of planning to destroy things that aren't weapons but are important to your opponent, such as population centers, industry, natural resources etc. Countervalue targeting is the foundation of the practice of nuclear deterrence, or, if you prefer (I don't), MAD. Its antonym is 'counterforce' targeting.

Countervalue is typically easier to do than counterforce, because your targets are typically soft (unprotected from blast or other nuclear weapon effects) and sometimes large (such as cities). Both characteristics mean that you don't need very complex and/or accurate delivery methods to attack them.