SatansMaleVoiceChoir
Illuminator
It seems to me we have two basic choices:
1) Ignore the suffering inflicted by such groups as the Taliban, Al Qaeda and those who perpetrate honor killings.
2) Do something about these groups.
We already agree that we cannot force societies to change be way of military force, although military force might be effective against military wings of organizations like Al Qaeda. That leaves such actions as education - particularly of women, raising their standard of living, making foreign aid conditional, sanctions and other pressures. I can see no reason to refrain from doing any of these.
I agree to extent with '2', but with the caveat 'only if our assistance is required'.
You also use the word 'groups'; these are not groups, but entire cultures (or AN entire culture). It's easier to change the mindset of a small group as opposed to a vast culture spread out across many countries.
As has already been pointed out, Honour Killing is already illegal in most of the countries that practice it, to a varying degree. The best you could hope for would be to assist those who want change into pressuring for tougher sentences, and providing them with the ability to educate their people.