A bayonet (from French baïonnette) is a knife, dagger, sword, or spike-shaped weapon designed to fit in, on, over or underneath the muzzle of a rifle, musket or similar weapon, effectively turning the gun into a spear. In this regard, it is an ancillary close-quarter combat or last-resort weapon.
However, knife-shaped bayonets—when not fixed to a gun barrel—have long been utilized by soldiers in the field as general purpose cutting implements.Modern use
The advent of modern warfare in the 20th century decreased the bayonet's usefulness, and as early as the American Civil War (1861–65) the bayonet was ultimately responsible for less than one percent of battlefield casualties. Modern warfare, however, does still see the use of the bayonet for close-quarter fighting. The use of "cold steel" to force the enemy to retreat was very successful in numerous small unit engagements at short range in the American Civil War, as most troops would retreat when charged while in the process of reloading (which could take up to a minute with loose powder even for trained troops). Though such charges inflicted few casualties, they often decided short engagements, and tactical possession of important defensive ground features. Additionally, bayonet drill could be used to rally men temporarily discomfited by enemy fire.
The British Army performed bayonet charges during the Falklands War (see Battle of Mount Tumbledown), the Second Gulf War, and the war in Afghanistan. Recently in Iraq at the Battle of Danny Boy, the Argyll and Sutherland Highlanders bayonet charged mortar positions filled with over 100 Mahdi Army members. The ensuing hand to hand fighting resulted in an estimate of over 40 insurgents killed and 35 bodies collected (many floated down the river) and 9 prisoners. Sergeant Brian Wood, of the Princess of Wales's Royal Regiment, was awarded the Military Cross for his part in the battle. This engagement brought to notice the tactical use of the weapon for close combat and the sheer psychological effect it can have. Similarly, in 2009, Lieutenant James Adamson, aged 24, of the Royal Regiment of Scotland was awarded the Military Cross for a bayonet charge whilst on a tour of duty in Afghanistan: after shooting one Taliban fighter dead Adamson had run out of ammunition when another enemy appeared. Adamson immediately charged the second Taliban fighter and bayoneted him.
During the Korean War, Lewis L. Millett led soldiers of the US Army's 27th Infantry Regiment in taking out a machine gun position with bayonets. Millett was awarded the Medal of Honor for this action. This was the last bayonet charge by the US Army.
All three situations demonstrate that the bayonet remains an effective and psychologically powerful last resort weapon even on the modern battlefield.
In 2010, the U.S. Army began a shift away from bayonet assault training and instead focus on training with pugil sticks. This is because the "last time the U.S. had a bayonet assault was in 1951". In the U.S. Marine Corps, recruits at the Marine Corps Recruit Depot in San Diego still get their first instruction in using the bayonet as a lethal weapon on their 10th day. The essence of bayonet fighting as taught in the Corps is to spring forward from a modified crouch and thrust the blade into the enemy. Recruits are taught how to use a bayonet to push aside an enemy's weapon.
In a modern context, bayonets are used for controlling prisoners and as a "last resort" weapon for close quarters combat e.g. situations where a soldier has run out of ammunition, or if his weapon has jammed or is damaged.
In general, bayonets are not fitted to weapons except when such emergency situations are at hand. This is because a bayonet will impair long-range accuracy. The reason for this is because the extra weight of the bayonet affects the balance of the rifle barrel, which alters its sighting characteristics. For example, bayonet-equipped Mosin-Nagants were normally sighted in at the factory with the bayonet fixed because Russian doctrine at the time specified that the bayonet should normally be fixed.
A bayonet remains useful as a utility knife, and as an aid to combat morale. Training in the use of the bayonet has been given precedence long after the combat role of the bayonet declined as it is thought to increase desired aggressiveness in troops. Despite the limitations of the bayonet, many modern assault rifles retain a bayonet lug and the weapon is still issued in many armies.