There is no rule of engagement regarding shooting the enemy in grave yards, but the rules of the Geneva Convention are so vague that it lays all operations open to charges from the World Court. The President of Serbia is not the only one that can be charged with war crimes, our own President and his administration is subject to the same danger, much less some General or Lt. in the field trying to fight a war.
The whole situation is STUPID.
Hanabal to his best friend just after the Battle of Zama (words to the effect as I don't have the reference book with me): "They (Romans) are killing the wounded and prisoners as we speak, we would not have done so if we had been the victor...but there is none to stop them"
My point: "our president and his administration" is leading the most powerful nation the world has ever known; so whom could ever make a charge of "war crimes" stocl?