This document discusses the risk assessment of chemical, biological, radiological, and nuclear (CBRN) threats in South-east European countries. It provides an overview of the types of CBRN weapons, how available they are globally, and the potential threats they pose. The main threats are considered to be chemical and biological weapons. While stockpiles of nuclear weapons are decreasing among major powers, some countries and groups are still trying to acquire them. The document analyzes the European Union's interest in and policies around CBRN non-proliferation over time. It outlines different aspects of the perceived CBRN threat to the EU and South-east European countries from the perspective of international security documents.