Final answer:
The UN intervened in the Congo after 1960 independence by sending peacekeeping forces to maintain order, but did not involve itself in preventing Katanga's secession, Joseph Mobutu's rise to power, or interact directly with the assassination of Patrice Lumumba.
Step-by-step explanation:
The UN's role in the Congo after independence in 1960 notably included sending peacekeeping forces to restore order and to protect the sovereignty of the newly independent state. While the UN forces were not directly involved with the assassination of Patrice Lumumba, or expressly with the prevention of Joseph Mobutu from seizing power, their presence was intended to stabilize a nation in upheaval due to internal conflict and the pressures of Cold War geopolitics. The United Nations did not actively engage in the cessation of Katanga’s secession due to their stance on non-interference in internal political matters, and they were not involved to prevent the intervention of the Soviet Union. Concerning the Belgian troops, their role was more to prevent the chaos that followed the immediate withdrawal and mutinies rather than to remove Belgian troops trying to retake control over the Congo.