The UN has compiled decades of experience in peacekeeping, and has noted two things that are leading to more women being recruited for peacekeeping operations. First, there's a shortage of qualified personnel. Just sending a bunch of guys with guns out to do "peacekeeping," often does not work. You need people with language and social skills, and women tend to have more of that. Another factor is that in many of the trouble spots peacekeepers are sent, the local women often operate their own information, economic and political networks. For example, in many cultures, there is a female version of the language which is quite different from what the men use. Female peacekeepers are much more likely to connect with the local women, and enlist them in peacekeeping efforts.
Currently, UN peacekeeping operations are 27 percent female for the civilian staff, but only one percent for the military and four percent for the police personnel. It's the soldiers and police who do most of the face-to-face "peacekeeping" with the locals, and that's where more women are needed.
The situation is similar to what happened several decades ago when police departments began recruiting more women. The police soon realized that one of the most valuable skills for a police officer was the ability to defuse disputes. Indeed, domestic disputes ( husbands and wives getting violent with each other, or their kids) are the most dangerous for cops (because there are many more domestic disputes for cops to deal with, than armed robbery or people running around with weapons.) Women excelled at defusing these disputes, and it appears those skills work in a similar fashion for peacekeeping missions.