Fratricide is a word that many historians and war observers regularly discuss, and it is a term that has evolved over time, as civilizations have risen and fallen. The original meaning of the term is the killing of one's own brother, and the Bible has pinpointed it as the first kind of murder that was ever committed, through the fable of Cain and Abel. The term itself is a combination of 2 Latin words, the noun frater, which means brother, and the verb cide, which means to kill.
Fratricide takes on a different meaning when looked upon as a military term; the other version is still closely related to the original concept. It is synonymous with the term 'friendly fire', which literally means the killing of one's own comrades inadvertently, while firing at the enemy. This concept should not be confused with 'collateral damage' (which refers to civilian damage and loss of life caused due to the actions of troops), nor should it be confused with the deliberate and intentional killing of one's own troops. Friendly fire is said to occur only when one's own troops are accidentally killed while shooting at enemies.
Many large empires involved fratricide in some manner, mainly so that a ruler would never be under any threat from his brothers who could potentially usurp him for the throne. The first instance, though, was seen in the Bible, when Cain murders Abel (both were the sons of Adam and Eve) based on jealousy.
Even Roman history has a crucial place for fratricide, as Romulus murdered his twin brother Remus to become the ruler of Rome. Both were the original planners of the Eternal City, and a dispute over the location of the empire led to the murder of Remus. The Ottoman Empire took this concept a step further, and made it imperative for all brothers and sisters of a new Sultan to be either murdered or imprisoned. Incidentally, the killing of one's own sister is known as sororicide, from the Latin for sister, soror; the word 'sorority' ring any bells now?
In the Military
As already mentioned, the term refers to the accidental killing of one's own comrades during an armed conflict. The large-scale scope of modern warfare and weapons has made this concept all the more prevalent, and this is a harsh reality that has to be dealt with. The military then assigns a tribunal to investigate the exact cause of the deaths, so that such incidents can be avoided in the future.
The biggest cause of friendly fire is miscommunication while the enemy is actively being engaged, and this makes the tragedy unavoidable. The problems of combat stress and poor terrain also lead to this incident occurring time and again. Proper coordination and planning is necessary during combat to ensure that this incident is avoided at all costs.
Fratricide is relatively common in the military, and every major war has had numerous instances of it, on both sides of the warring factions. Wars such as the Vietnam war (1955 - 1975), the Gulf War (August 1990 - February 1991), and the Iraq War (2003-2011) were also notable for the number of deaths caused by friendly fire. There were even some instances of American troops killing British soldiers by mistake!
The killing of one's brother, sometimes condoned in olden times, is obviously illegal now, and it amounts to murder and homicide. Friendly fire is a different kind of animal altogether, and it is something that is, sadly, unavoidable when two nations go to war.