This is an expression said to describe false or insincere display of emotion such as a hypocrite crying fake tears of grief. This expression comes from an ancient anecdote that crocodiles weep in order to lure their prey or that they cry for the victims they are eating.
As Wikipedia tells; one prominent use of the expression is by Shakespeare in his Othello.
Last Wednesday the US envoy to both Sudan and ROSS Princeton Lyman,  shed crocodile tears when he said that he is sad because of the state of unrest in the bilateral relations between US and Sudan!! . Dear reader I am sure you will faint because of surprise on reading Lyman's words.
Of course no one in the world can believe this lie, simply because US was behind this state of bad relations between the two countries.  I ask Lyman if he really feels sad to ask himself a question who is behind sabotaging the US – Sudan ties. Weren’t US that imposed economic sanctions on Sudan? Who enrolled Sudan on the black list of states sponsor terrorism? Who struck Al-Shifa factory for medicine in the heart of Khartoum on the bases of false information? Who cheated Sudan by promising to remove its name from the list of terrorism but recoiled? Wasn’t it US which pledged Sudan to normalize ties with it in condition that Sudan performs the referendum of South Sudan and accept the results, but retreated after Sudan fulfilled the conditions? .
I wonder why Lyman feels sad. Why he cries over the spilt milk and shed crocodile tears. If US really want to build good relations with Sudan, the ball is now in its yard. Sudan has nothing more to do; Sudan has no pious act or oblation to administer it to US. Sudan ran out of any sacrifices for the sake of US consent. I call on Lyman and his alike to spare his sadness and to dry his tears; no one believes in US faithfulness.