How important is the UN Security Council in deciding whether or not an intervention will take place?

The topic question is : How important is the UN Security Council in deciding whether or not an intervention will take place? Support your answer with examples from the case studies. 3- it is very important to use case study and evidence in the essay I want you to use ( syria and Libya) UN intervention as a case study like Nato intervention , and other things like stoping weapons to Libya … at the end I want you to use and focus on the un security council resolution at those two countries … and to show how important did it change the situation. 4- please do not exceed the word limit which is 2250 word