The available pool of UN peacekeepers is heavily influenced by two factors. First, there is a relatively fixed stock of global military resources suitable for UN peacekeeping. Moreover, this stock is significantly smaller than often surmised with one estimate suggesting that the ceiling might be around 210,000 troops.⁹ Key limiting factors include the presence of large numbers of conscripts in many armies, rotation demands, training and expertise requirements, and the suitability of forces for peacekeeping.
Second, states have choices about where to send their troops. They can choose to send personnel to:
UN-led missions—authorized by the UN and under...