483. When is it morally permitted to use military force?
The use of military force is morally justified when the following conditions are simultaneously present:
- the suffering inflicted by the aggressor must be lasting, grave and certain;
- all other peaceful means must have been shown to be ineffective;
- there are well founded prospects of success;
- the use of arms, especially given the power of modern weapons of mass destruction, must not produce evils graver than the evil to be eliminated.
(Compendium of the Catechism
of the Catholic Church)
Are there "well founded prospects of success" for Ukraine against Russia?
Without massive and continuing American financial support for Ukraine's war effort, the answer certainly appears to be an unqualified "no."