War - Just war theory

Who made this theory?

St Thomas Aquinas

What is this theory?

A war should only be fought for a cause that is morally justified

Jus ad bellum

• Last resort - War must be the last resort

• Legitimate authority - War must be lawfully declared by a government with the authority to declare war

• Just cause - There must be a just cause and proper intention for the war

• Reasonable success - There must be a reasonable chance of success

Jus in bellum

• Good outweighs evil - The good gained by winning the war must be greater than the evil caused by fighting it

• Proportionality - there must be proportionality, only ‘appropriate force’ should be used.

• Innocent shouldn’t be killed

• Peace restored at the end