Conflict Resolution: What do you do when the kids argue?

Okay, so it happens and this video got me thinking about what to do when our own kids argue in the classroom.
I love to post about the fun and good times we all have in preschool, but there are clearly times where we as teachers need to step in and help kids problem solve.

"I said, NO! And I mean it!"

Conflict resolution is a beautiful thing when the kids argue. Much of the time they need a bit of help and guidance from us during an argument.
I say this because even in the happiest classrooms, it's not a matter of if, but when an argument erupts.

We would like to hear about about tried and true solutions for conflict resolution within your classroom!
So, how would you handle this situation in the video?
Would you have intervened? If so at what point?