Some of us were protesting the war in Yugoslavia in the streets of our cities.

You seem to imply that the terror in the Balkans was an internal issue, not caused or fuelled by external intervention, or in part armed by western powers. I think the reality is closer to this paragraph from wikipedia[1]:

"The Bosnian government lobbied to have the arms embargo lifted, but that was opposed by the United Kingdom, France and Russia. US proposals to pursue this policy were known as lift and strike. The US congress passed two resolutions calling for the embargo to be lifted but both were vetoed by President Bill Clinton for fear of creating a rift between the US and the aforementioned countries. Nonetheless, the United States used both "black" C-130 transports and back channels, including Islamist groups, to smuggle weapons to Bosnian-Muslim forces, as well as allowed Iranian-supplied arms to transit through Croatia to Bosnia. However, in light of widespread NATO opposition to American (and possibly Turkish) endeavors in coordinating the "black flights of Tuzla", the United Kingdom and Norway expressed disapproval of these measures and their counterproductive effects on NATO enforcement of the arms embargo. Inter Services Intelligence also played an active role during 1992–1995 and secretly supplied the Muslim fighters with arms, ammunition and guided anti tank missiles to give them a fighting chance against the aggression."

A simplistic view that there were evil Serbians and good Bosnians seems a bit naive. I think there are some strong parallels with how the Mujahideen were "good" when fighting Soviet, and are now "evil" when fighting NATO. It's a compelling fiction, but it's not how the real world works. The real world is more like:

https://en.wikipedia.org/wiki/DynCorp#Bosnia_incidents

Just moving in with military force and expecting a Hollywood ending is completely unrealistic. How do you stop a genocide in a civil war? By committing genocide against the "offending" party?

And while I opposed the UN/NATO intervention (a landmark bending of the UN charter in favour aggression) your comment also seem to belittle the role of European troops in the peacekeeping effort. I have nothing but respect for those that served, even if I have mostly contempt for the politicians that sent them there.

Lastly, I don't see much point in creating a competition of guilt. As you ask:

> are not European citizens complicit in the genocide that they let happen

Most certainly. We're also complicit in the murder of Iraqi , Syrian, Libyan and Afghan children, as we've been unable to stop the wars our government participates in, for some vague geopolitical agenda. But that doesn't change the fact that the US controls the largest war machine the world has seen, and seem more than willing to wield it with impunity across the globe.

It can be hard to fight off apathy and frustration when you pay taxes to a system that keeps killing (mostly innocent) people for what apparently seems like not very good reason, and perhaps even worse, based on very poor intelligence and complete disregard for history (What, the British were surprised at the situation in Afghanistan, after having been at war there for a hundred years or more? No one reads Kipling any more?).

But just because many things are terrible, doesn't mean one should stop to try to do good. But the opposite, in such times, everyone must do what they can. If everyone does something, then something can be done.

[1] https://en.wikipedia.org/wiki/Bosnian_War#Warring_factions