For one EU and US have fairly many converging security issues and goals. Thus working together in common security issues does make sense.

For second, EU countries have been VERY worried of threats from middle-east including ballistic missiles (notice steady work on SAM systems that allow defence against theatre level missiles) and increase of naval co-operation in Mediterranean (and talk of counterimmigration co-operation).

EU clearly does not like idea of nuclear armed Iran with reason being that it is believed that all other countries in region would also try to get themselves nuclear weapons too.

At the same time US does appear quite willing to use weaponry (including nuclear weapons) to pre-emptively stop Iran from gaining its own nuclear weaponry. this has been made clear in various doctrinal documents and major foreign policy speeches. I am absolutely certain that at least some of these leaks in recent years are intentional and used to signal change in nuclear policy stance in order to deter potential enemies. I have not seen such concepts being floated around in EU and thus I believe there is a fundamental difference between US and EU policy options towards Iran. I believe this means that EU(3) can and do put diplomatic pressure while US can and does employ military pressure (including airspace violations, armed military units infiltration) up to and ultimately including air strikes. I also believe, based on military doctrines and diplomatic leaks that US will ultimately use force against Iran in some form.

I also believe that EU strategists do strongly believe that US will sit on Middle-East for several decades no matter what the cost or casualties because importance of that area for global energy supply continuously increase. It is also good to remember that US sees China as future enemy (this view is particularly strong amongst US Navy in Pacific but it has also been signaled in 2000-2001 internal reviews on stregic postures that were leaked). Since China's reliance on Middle-East for energy supply is increasing, it is rational for US to keep its hand on tap. EU's ultimate Middle-East nightmare is also strongly related to this geostrategic choice. EU's ultimate fear is a revolution in Saudi-Arabia that will trigger US invasion to protect its oil interests in area. This has been voiced in several European publications. While this kind of calculation might appear machiavellian, it is good to remember that while supply is important, ability to deny supply is equally important, especially in crisis.

Subsequently I believe that EU has accepted US policy of military overlordship of Middle-East as a rational strategic choice (on behalf of US) and thus holding Iraq and isolation of Iran (also Syria) are rational policies for US.

Finally I believe that EU3's fundamental strategic goal and option to be supporting US on diplomatic front while avoiding outward military actions. For one EU does not have (yet) such capability (and will not for next 20-30 years) and for second such policies are not domestically popular.

I do also believe that EU does not want military strikes against Iran because perceived cons outweight pros. The perceived cons include destabilization of Middle-East and economic consequences of high oil prices. These two options (including third, that threat is not acute and isolation does work) were also cited by French authorities in 2002 before attack towards Iraq. I do see EU possibly supporting harsh language, diplomatic isolation and possibly economic sanctions as ultimate ways to deter Iran. I do not see EU going to give US keys to air strikes.

At the same time I also believe that EU countries have been signaled from US that US will ultimately go to military options within next few years. Subsequently EU countries have themselves thought over the issue and came into conclusion that they do not intend to stop war but do allow it to happen and try to stay away from it.

This gives best of all worlds by scoring cheap points with US (useful when next president comes in power), playing home constituencies by being outwardly pacifist and simply making the best out of worst options.

Such stance might appear to be hypochritical to some sensitivities but I believe it is rational course of action if you do believe military actions are coming anyways.

http://www.iss-eu.org/new/analysis/analy118.pdf

However, I would point out that at its most simplistic analysis, the Iranian conservatives would reap benefits from threat of confrontation.

Benefits include:

1. Ability to make quiet and marginalize internal dissent ("You're either with us or against us")
   
2. National pride that allows continuation and perhaps initiation of wanted policies
   
3. Iran is powerful regional player and future actions and national power could be reinforced with successful crisis settlement

You could say that outside obvious geopolitical advantages there are also several domestic political advantages for US administration to get into confrontation with Iran.

the cote d'ivoire occupation, where french troops along with some UN thugs are "peacekeepers" who stay against the wishes of the local govt and people

The French troops are the only thing preventing a genocide for now. I won't defend French policies in Africa, but this narrow one I have no problem with (of course, you could argue that the French presence is at the root of the reasons there would be a genocide, but considering how things stand, these troops are need now.

In the long run, we're all dead. John Maynard Keynes

if iran gets hold of non-conventional deterrents all westerners will be back to eating potatoes and porridge in winter, for the european prosperity rests in big part on the ability of our govts to rape other countries of their wealth.

Yes, the ownership of nukes by Russia (formerly, the Soviet Union) has indeed forced us to do without their gas for the past 40 years. Get real.

In the long run, we're all dead. John Maynard Keynes