The end justifies the means.
Provided. The means do actually lead to the desired and justified end. The end is itself justifiable. The means to the end do not cancel out the justification for the end.
E.g. To save a life is justifiable as an end. To chuck a nuclear missile at an aggressor does not secure the desired end as it kills the victim as well as the attacker. If the life is that of Cliff Richard the end is not justifiable. If to save the life of a decent individual you have to kill two other decent individuals (or worse still have to let Cliff Richard live) the desired end is cancelled out by the worseness overall outcome.
Provided. The means do actually lead to the desired and justified end. The end is itself justifiable. The means to the end do not cancel out the justification for the end.
E.g. To save a life is justifiable as an end. To chuck a nuclear missile at an aggressor does not secure the desired end as it kills the victim as well as the attacker. If the life is that of Cliff Richard the end is not justifiable. If to save the life of a decent individual you have to kill two other decent individuals (or worse still have to let Cliff Richard live) the desired end is cancelled out by the worseness overall outcome.
Your argument is basically that any horrors can be justified as long as they get the 'desired end'. Well that's a great excuse for those in power to do what they like.

