The Russian invasion of Ukraine has become a protracted war between Ukraine and Russia, with elements of a new Cold War where Ukraine’s western Allies are fighting Russia by proxy through the supply of weapons and other aid through the NATO alliance. The just war standard of “reasonable chance of success” is not part of the original theory devised by Saint Augustine or St. Thomas Aquinas, but a later innovation made by Francisco Suárez to prevent wars from deteriorating into a long cycle of revenge by parties at war.
