The internal Iranian politics are pretty much two sides of the same coin, the reformists and "conservatives" do not offer that many differences. I certainly think that a stable, secular and democratic Iraq will benifit the region broadly, you cannot bomb democracy into every last country, but if you secure one and pour efforts there and suceed - it will be a reverse domino effect and unlike the false analogy of the domino effect in Indochina falling to communism the benefits in this case will give the effort momentum. The only way to win the GWOT is to remove the support that the Islamists recieve, not by sitting on your hands and waiting to be attacked, not by backing more bastard dictators to supress dissent rather providing a genuine alternative to political Islam, I think that the 20th Century shows that liberal democratic principles build on the foundation of universal human rights and equality is that system, it works - simple as that, transformed Europe, built America, remade Japan. I think that the change of Turkey from the Caliphate to a secular democracy and the sucess to be found demonstrates that one can strike a seperation of the powers even in the ashes of theocracy. There is no reason to assume that simply because the Arab world today is filled with Cold War hangovers from both the USA and USSR, religious fanatics and poverty that it cannot get better. Human beings are more or less the same the world over and if they can be safe and prosperous then concepts of democracy and liberty appear very quickly (case in point Indonesia during the economic meltdown, the new middle class was able to initiate political change against Soeharto which brought about more political freedoms).
The concequences of inaction tragically tend to be greater than those of action (WWII for instance occured due to the tempered view of peace in our time, Rwanda was an example of inaction - it is a tragedy of history that there is no magic wand but we must live in the world as it is to make it what it can be) I am not saying that this justifies all action Cart Blanche rather that we are faced with a unique threat and we must come up with a no bullshit solution for it. I think that the solution is liberalisation of the Arab/Muslim world - not to remake them in the image of the west with Starbucks, internet porn and Coca Cola - but general political freedom, economic development and good leadership. It has been working in Asia very well to this day and does not constitute some sort of imperial conquest to subjegate and enslave populations.
I am not saying that we should conquest every dissagreable nation and rain fire down upon every last enemy state and justify it in some vague axiom of "freedom". That would lead to failure, simple as that. Do it and do it properly in very specific cases (such as Iraq, where we are allready far in), it is like a foothold.