Because we human cannot still prevent a war from happening after thousands years of history with too many of them them. Once a war happens freedom and basic human rights are easily viorated and too many terrible things happens for humans beings.
The best way must be that we, normal civilians, prevent it because the victims are mostly normal civilian. If there are enough people, who are aware of how bad wars were and understand how they happened, we must be able to avoid to follow the same path again. But in reality it is not easy. The damage of a war is so bad that nobody wants to talk about it. Then after some time we don't remember any more and we let it happens again somewhere else. It is a vicious cycle. As far as I know, people in democracy never voted directly to go into a war, but we've never prevent a war, either. We could demonstrate against a war only after an atrocity became evident, but that is too late for victims.
So let's Break the Slience about wars and human rights violations.
Let's see how the Silence occurs.
When a war is over people becomes happy and talk about the war at least for a while, but not for long.
People who committed bad acts, such as killing, abusing, torturing, raping, etc, don't talk about it to save themselves from punishment.
People who ordered them to do it, who helped them, or who knew about it but not stopped, would not talk either.
Then the goverments and military organization do not dare to find out what happened or even to talk about them in order not to damage the pride and the interest of the country.
Also most of the victims usually don't talk, either. Nobody want to remember the bad experinces, and they wouldn't tell it especially to their loved ones in their family or friends. They do it sometimes only with the limited friends who went through the ellende together, but onl behind the closed doors.
Then other people, medias, schools, etc, lose interest after some years because in principle nobody want to hear about bad things. Some victims courageously speak up to ask for understanding from their country men, but they are not really welcome. Politicians don't bother because they cannot get extra votes by doing so.
Then Silence spreads and dominates everywhere… Then by the time people forget about the war, a new war breaks out somewhere but most of us doesn't even realize that the same atrocity would happen again. Recently major human rights violations happens not only durin a war between countries, but also in new forms: war on terror, immigration problem within a country, Arab Springs (from Tunisia to Syria), Occupy movement all over the world, and even the nuclear crisis in Japan.
This vicious cycle of the Silence become especially evident about what their own country has done badly; Japan for what they did to POWs and civilians in vast East Asia before 1945, the Netherlands for their military intervention against Indonesia after their declaration of independence in 1945 ( so-called Police actions, or Politionele acties in Dutch) and for the colonial period, USA for what they in Vietnam, Afganistan, Iraq, etc. As far as I know only Germany has succeeded in confronting their own negative history. It must be almost too difficult for us humans.
We simply have to discover a way to confront with own own negative history and to learn from it, in order not to make the same mistake agin. So we should break the Silence, but this is a resilient enemy. Peace activists and scholars have been trying to talk about it, but they voice is not loud. We, normal people, should somehow contribute it, too. And it is important to find a sustainable way so that we can keep on doing, otherwise the Silence wins.
Let's break the Silence, because this is the only way out!
Our conclusion is that we need a specific Dialogue, to do this.