While most people have lost trust in their governments. It is still imperative that the world continues to make the effort to bring piece to the world. Wars are expensive and cost many lives over non sense. Which leads to more people's anger, increasing the chances of more wars to break out. Which can calamity to every economy on Earth.
Yes, the US should support UN peacekeeping operations, because a mission that comes from an international consensus has international backing. When the entire UN is behind a mission, it is very powerful, and is more powerful than the United States acting alone. The UN would also contribute to the cost of the mission, which is financially beneficial to the United States.