Given that the world is a dangerous place and peacekeepers are deployed for just that, to keep the peace, I submit 'the robotic peacekeeper.' If anyone watches the show 'robot wars' or does a casual web search on robots, you will find a wide variety of chasis and platforms available.
The UN (or unilaterally
the US) can deploy a base model robot chasis (think something along the lines of the mars rover, encased in kevlar, with internal power), with various sensors, speakers, and even weapons. The idea is to patrol an area with an array of sensors and possible defense capability.
Perhaps a demilitarized zone or border can be patrolled by a platform with heatseaking capability. When a warm body is detected, the video/infrared cameras can be turned on and the object can be monitored. If it shoots at the robot, the robot should have the speed to get away, or the firepower to 'supress' its attacker.
The variations are endless. Robots that can listen for speech, (the 'remote pilot' can) determine if its friend or foe, and deploy gas grenades. Picture robots that are smaller than a skateboard zipping in and out of an area in search of insurgents. Picture 'bots that sit along the side of a road or trail and listen for digging or foot traffic. Once awakened, they can send back observational data about who and what is going on. With the proper camoflauge and attachments, they can burrow themselves into the sand like crabs and monitor for days on end.
Beautifully the human element is 10's or 100's of miles away watching via a satellite, cellular, or microwave uplink,and the bad guys only get the satisfaction of breaking a moderately priced toy.
In all cases, friendly lives can be saved as well as funds. A soldier costs ~50K to train for 1 year. An armored robot with eyes and ears ~5K. And robots don't get scared, get sick,or worry about their families.
The ultimate peacekeeper.