Good questions DoDo.  I think we all agree that the Petersberg tasks are appropriate, but many countries lack the logistical capabilities they need.  I also think that the western countries need to be better at supporting refugees and emergency reconstruction, but I don't know whether these tasks below to the Army or some civilian agency.  

There are still plenty of situations that require conventional military force.  For example, none of us wants to see China invade Taiwan, or North Korea attack South Korea, or Serbia attack Croatia.  NATO membership may be the only thing that protects the Baltic states from a future Russian government.  While I'm not familiar with the details of Falklands diplomacy, I think that in principle, the British were justified in using force to repel the Argentine invaders.  I also think that evacuating expats is a legitimate use of state power.

I am aware that the western countries have frequently used their militaries to set up right-wing military dictatorships around the world.  This practice has almost always backfired on us, and I hope that our leaders will eventually realize that it is futile.  (Not to mention hypocritical, un-democratic and just plain evil.)  Nevertheless, if dictatorship stays in our sphere of influence long enough, sometimes it can transform into a democracy; Taiwan and South Korea are prime examples.

I really don't know what to do about humanitarian crises like Sudan or Rwanda.  We have a moral imperative to help the weak, but I don't think we know how to do that sucessfully.  One of my friends spent 20 years in the military, and now he works for NGOs in crisis zones - he doesn't have any easy answers either.

So there are some of my thoughts on the uses of military power.  How much money should a democracy spend on these tasks?  I think 4% of GDP is too much, and 1% is too little, but every country has to decide that for themselves.