Friendly fire

Friendly fire (non-hostile fire) is United States military parlance for fire from friendly forces as opposed to fire coming from enemy forces known as "enemy fire".

A "friendly fire incident" refers to a military situation where forces or material assets of one side are attacked and damaged in error by those of their own or their allies. In British military parlance these incidents are referred to as blue-on-blue. The term "blue-on-blue" originates from wargaming exercises where friendly forces are blue and enemy forces are red. The term fratricide (killing one's brother) is also sometimes used but more properly refers to deliberate attacks upon one's own forces.

Friendly fire incidents fall roughly into two classes. The first is due to errors of position, where fire aimed at enemy forces accidentally ends up hitting ones own. Such incidents were relatively common during WW2 and WW1, where troops fought in close proximity and targeting was relatively inaccurate. The second class is errors of identification, where friendly troops are mistakenly attacked in the belief that they are enemy. This class is more common in recent times, where weapon accuracy is greater. It is also more common in highly mobile battles, and battles involving troops from many nations.

Rightly or wrongly, the armed forces of the US are widely believed to be more prone to friendly fire incidents than the military of other nations. The Pentagon estimates at US friendly fire deaths are:

• WW II: 21,000 (16%)
• Vietnam war: 8,000 (14%)
• Gulf War: 35 (23%)
• Afghanistan (2002): 4 (13%)