Then you'd serve a few extra years for kidnapping. Don't you understand something as basic as not forcing people to do something against their will? Their planet might lie in Federation space but they are not Federation citizens and you have no authority over them. The Federation is not a galactic rapist.
If they don't want your help you are not obliged to protect them in any way. The Federation is not a galactic nanny. You basically say it is justified to walk around and pull the cigarettes out of the mouths of smoking people and trample on them because you care about their health, because you can better protect them than they can protect themselves.
If foreign powers are really willing to start a war with the Federation in order to conquer Ba'ku, merely a hypothetical scenario and not the inevitable course of history, you have other things to worry about anyway and the Ba'ku might not be safe at the new planet to which you transported them either. Not to mention that they would sooner or later start to rot like the So'na and die without the radiation from the planet.
At the end of the day abducting the Ba'ku still serves only one purpose, to move them away from the precious resources we want to get our hands on. Trying to cover this crime with claims to actually care about their well-being is even more wicked than Dougherty's position, he did at least acknowledge that the Ba'ku are violated.