From the Islamic point of view, that is, rather than the Machiavellian one.
It's a worthwhile question--can you do something that is haraam in order to achieve an admirable goal? I just recently heard a rather strange hadith (which has not been authenticated, so I won't relate it) that caused at least one person to draw the conclusion that it is okay to adopt a reprehensible method of obtaining a noble objective. Hearing it for myself, I didn't see at all how the person came to that conclusion.
But the more the discussion progressed, and it seemed that this was precisely the case (i.e., haram means for a good end), I remembered how my shaykh had recently mentioned more than once in recent classes that the end does not justify the means.
We were talking specifically about the seerah--the biography of the Prophet Muhammad (pbuh). For years the Muslims were being persecuted in Mecca, and the Prophet (pbuh) was offered by his enemies leadership in the city, but he refused. It seems like a very strange decision, doesn't it? As it was, only the poor and weak were accepting his message, but maybe if he were in a position of authority more people would be guided to Islam. Right?
But he didn't accept it. I guess you could say that Allah had a plan, and it wasn't for the Muslims to become dominant by a deal with the mushrikeen. The Muslims were able to establish a state (i.e., in Medina) only through da'wah, because of people accepting Islam and accepting the Prophet Muhammad (pbuh) as their ruler.
Nowadays we don't have the Islamic state, so our position is analogous to that of the Muslims in Mecca, before the migration to Medina. And yet, we (at least, most of us do, right? or some of us?) want an Islamic state, a khalifah, a way to implement Islam fully at all levels of society. That is the "end." And the "means" obviously are the different routes by which some people might attempt to establish such an Islamic state: democracy, perhaps, or a military coup, perhaps invasion, or some might even say jihad.
But when we look at the life of Muhammad, do we see any of those routes to establishing the Islamic state? Nope. What do we see? Da'wah--only da'wah. The Prophet Muhammad (pbuh) did not use any sort of military or violent jihad to establish an Islamic state--so how is it anyone can argue that we should do it today? We shouldn't, it's pretty simple.
The end does not justify the means.
And I've yet to see any evidence suggesting otherwise in any other part of life, in any other aspect of Islam. So I imagine the prudent path here is to ask Allah for forgiveness for our sins and mistakes in the past, and to make it easy for us to remain firm on the Straight Path.