UN Charter combines all three approaches-peacekeeping, peacemaking, and peace building- into the UN's structure, other organizations like the Organization of Security and Cooperation in Europe (OSCE), the High Commissioner on National Minorities (HCNM), and/or different non-governmental organizations (NGOs) focus on preventive approaches for dispute settlement because of cost as well as risk effectiveness.(Sezai Özçelik, 2006: p107) .

The UN is doing its best but is depending on the major political actors such the current presidents Trump and Putin...

Thanks for the discussion

Imad Khaleel Ibrahim has asked

"Does preventive diplomacy of the United Nations relate to the reconstruction of peace in States emerging from armed conflict only?"

A clear answer: NO. UN peace troops also try to stand between conflict parties, a popular example was Cyprus (Greece vs. Turkey).

But I fear it is all depending from the overall situation. And considering that you are based in Mossul/Syria, the syrian civil war is an adequate example of UN failure as is possible the annexion of the Crimmean by Russia (in the Ukraine)...

As I said before: the UN is an assembly of all that is rund by five nuclear powers with veto rights... These major stakeholders are the ones that are in charge of UN failures, not the UN as a whole in my view...

The contemporary practice in preventive diplomacy at the UN in essence heavily depends on the issue the major powers deem to be important. Despite the good intention of the UN, each of the major powers look at the world from their own unique perspectives which has created more divisions and turbulence. Hence, major problems go unsolved. Preventive diplomacy could be successful if the US/Russia/China agree on one vision and a course of action. The UK and France usually but not always follow the American lead.