Each nation on this planet has the right to determine its own destiny. The people within the borders of each country can choose to deal with oppressive regimes and choose their own form of government. Intervening in the direct political affairs of other countries to affect regime change is morally wrong and illegal under international law. Non-intervention is justifiable in every sense of the concept.
I think it is perfectly justifiable to not intervene in others affairs everyone including a whole nation because people have the right to decide what is best for them and to choose their friends and or allies even if it ends up being not the best decision it is still theirs to make.