Cease fires are called for a number of reasons; none of which are to spur on the singing of a John Lennon song.  Maybe you missed these points in your tactics classes. 

Let's collect on the ground intel.
Let's reposition our forces.
Let's watch the very next movement of enemy forces.
Let's protect these citizens.
Let's repair this strategic line of communications.
Let's insert snipers and overwatch.
Let's work together.