In World War II, children frequently fought in both the Allied and Axis forces in formal and informal military roles. Children were readily indoctrinated into the prevailing ideology of the warring parties, quickly trained, and often sent to the front line; many were wounded or killed. The lack of a legal definition of a child, combined with the absence of a system for verifying the ages of prospective child recruits, contributed to the extensive use of children in the war.

Use of children German armed forces Hitler Youth Hitler Youth (Hitlerjugend) was established as an organization in Nazi Germany that physically trained youth and indoctrinated them with Nazi ideology to the point of fanaticism. Even at the onset of war, the Hitler Youth totalled 8.8 million members. Numbers decreased significantly (to just over one million) once the war began, as many local and district leaders were conscripted for the national army."Hitler Youth" , The History Place, Retrieved on 15 April 2015. The previous average age for local and district leaders was 24, but following the onset of war, this had to change to those who were 16 and 17 years of age. These youths were in command of up to 500 boys.

Near the end of the war, one Hitler Youth soldier, Heinz Shuetze aged 15 from Leipzig, was only given a half-day of training with a Panzerfaust. He was immediately given an SS uniform and directed to the front lines to fight.Hill, Allan. "Revealed: The Tragedy of the Nazi Child soldiers rounded up from school", Express, Retrieved on 17 April 2015.

Huge numbers of underage males were removed from school in early 1945, and sent on what were essentially suicide missions."Revealed: The Tragedy of the Nazi Child soldiers rounded up from school", Express, Retrieved on 17 April 2015. Hitler Youth activities often included learning to throw grenades and dig trenches, bayonet drills and escaping under barbed wire under pistol fire; the boys were encouraged to find these activities exhilarating and exciting."The Hitler Youth" , British Pathé, Retrieved on 20 April 2015. The Hitler Youth was essentially an army of fit, young Germans that Hitler had created, trained to fight for their country. They had the "choice" either to follow Nazi party orders or to face trial with the possibility of execution.

The boys of Hitler Youth first saw action following the British air raids in Berlin in 1940. Later, in 1942, the Wehrertüchtigungslager or WEL (Defense Strengthening Camps) were created in Germany; they were designed to train Hitler Youth boys aged 16–18. They learned how to handle German infantry weaponry, including hand grenades, machine guns and hand pistols. By 1943, Hitler Youth boys were facing the forces of Britain, the United States and USSR."Hitler Youth" , The History Place, Retrieved on 19 April 2015.

Even younger boys from the ages of 10–14 years could be involved in the Hitler Youth movement, under the Deutsches Jungvolk."The Hitler Youth" , British Pathé, Retrieved on 22 April 2015.

Girls were also involved in Hitler Youth Operations, although in a limited capacity, through the Bund Deutscher Mädel (BDM, the League of German Girls). Avoiding direct armed conflict, their primary role was to produce healthy, racially pure baby boys."Hitler Youth" , The History Place, Retrieved on 20 April 2015. They were also required to run 60 metres in 14 seconds, throw a ball at least 12 metres, march for 2 hours and swim 100 metres.The History Place, Retrieved on 19 April 2015.

SS Youth Division Towards the end of the war, the Germans established an entire SS Panzer Division with the majority of its recruits being 16- and 17-year-old boys from the Hitler Youth brigades.Eigen, Louis D. "Child Soldiers Are Unfortunately Nothing New" , Scriptamus, Retrieved on 23 April 2015. In the 1st Battalion over 65% were under 18 years old, and only 3% were over 25."World War II: 12th SS HitlerJugend Panzer Division Fought in Normandy" , HistoryNet, Retrieved on 23 April 2015. There were more than 10,000 boys in this division.

The 12th SS Panzer Division Hitlerjugend was established later in World War II as Germany suffered more casualties, and more young people "volunteered", initially as reserves, but soon joined front line troops. These children saw extensive action and were among the fiercest and most effective German defenders in the Battle of Berlin."Child Soldiers Are Unfortunately Nothing New" , Scriptamus, Retrieved on 2 October 2014. In the battle of the Normandy beaches, the division suffered 60% casualties, most of whom were teenagers.Latimer, John. "World War II: 12th SS HitlerJugend Panzer Division Fought in Normandy" , HistoryNet, Retrieved on 24 April 2015.

Other German involvement

In late 1944, the People's Army was formed ("Volkssturm") in anticipation of an Allied invasion. Men of all ages, from 16–60 were conscripted into this army."Hitler Youth" , The History Place, Retrieved on 21 April 2015.

Children as young as 8 were reported as having been captured by American troops, with boys aged 12 and under manning artillery units. Girls were also being placed in armed combat, operating anti-aircraft, or flak, guns alongside boys. Children commonly served in auxiliary roles in the Luftwaffe and were known as flakhelfer, from luftwaffenhelfer.

Japan In anticipation of the possible Allied invasion of Japan, Japanese military authorities also trained young teenagers to fight the enemy with bamboo spears and other (often poorly) improvised weapons. Some Japanese children aged 17 years volunteered to be Kamikaze suicide pilots.Eigen, Louis D. "Child soldiers are unfortunately nothing new" , Scriptamus.wordpress.com, Retrieved on 26 April 2015.

The Japanese Imperial Army mobilized students aged 14–17 years in Okinawa island for the Battle of Okinawa. This mobilization was conducted by the ordinance of the Ministry of Army, not by law. The ordinances mobilized the student for a volunteer soldier for form's sake. However, in reality, the military authorities ordered schools to force almost all students to "volunteer" for soldiers, creating the . Sometimes they counterfeited the necessary documents of students. Many were killed such as in suicide attacks against a tank with bombs and in guerrilla operations.

After losing in the Battle of Okinawa in June 1945, the Japanese government enacted new laws in preparation for the decisive battles in the main islands. They were the laws that made it possible boys aged 15 or older and girls aged 17 or older to be conscripted into the army for actual battles. Those who tried to escape the call-up were punished by imprisonment.

The Japanese surrender, however, had forestalled the Allied invasion of the Japanese main islands, and therefore rendered these child soldiers unnecessary.

Jewish resistance During the Holocaust, Jews of all ages participated in the Jewish resistance simply to survive. Most Jewish resistance took place after 1942 when the Nazi atrocities became clear."Armed Jewish Resistance: Partisans" , Holocaust Encyclopedia, Retrieved on 24 April 2015. Many Polish political leaders fled Warsaw at the onset of war, and those who remained were generally executed, jailed or forced to serve on the Jewish Council (Judenrat)."Jewish Youth Movements in Wartime Poland: From Minority to Leadership" , Holocaust Encyclopedia, Retrieved on 24 April 2015.

Leaders of the Zionist Youth Movement who fled returned to Warsaw through a sense of responsibility as local leaders, for both youth in general and the wider Jewish community. More than 100,000 young Jews participated in resistance youth movements, despite the Germans outlawing such activity.International School for Holocaust Studies. "Youth Movements" , Shoah Resource Center, Retrieved on 22 April 2015.

The Zionist groups' focus changed with the onset of war. Before the war, they focused on social and ideological development. Feeling a higher sense of responsibility to their people during the war, they set out to educate their people by setting up underground schools in ghettos.

These leaders led a ghetto resistance, determining political and social action underground. Youth of the Zionist resistance were part of the Armee Juive (Jewish Army) in France, created in 1942, an armed Jewish resistance in Western Europe. They took part in the 1944 uprisings against the Germans in Paris.

Many members of the youth movement Hashomer Hatzair fought in the Warsaw Ghetto Uprising of 1943. Unlike many other instances of the use of child soldiers, participation of children in this armed resistance is usually regarded positively.Rosen, David. "Child soldiers: Victims or heroes?" , FDUMagazine, Summer-Fall 2005.

Soviet Union

A number of child soldiers served in the Soviet Union's armed forces during World War II. In some cases, orphans also unofficially joined the Soviet Red Army. Such children were affectionately known as "sons of the regiment" () and sometimes willingly performed military missions such as reconnaissance. Officially, the age of military conscription was lowered to 18 for those without secondary education and 19 for those with higher education.Simkin, John. "The Red Army" , Spartacus Educational, Retrieved on 23 April 2015. In 1943 and 1944, 16–17 years old boys (born 1926–27), many from Central Asia, were conscripted. These soldiers served in secondary units, not combat. Many were sent to the Far East, to replace units sent to the German front. After training and coming of age, these males were sent to the front too.

United Kingdom In the United Kingdom, boys of 17 were accepted into the Home Guard (popularly nicknamed "Dad's Army""The Home Guard" , Children's British Encyclopedia, Retrieved on 24 April 2015.) when it was formed in 1940 in preparation for a German invasion and as a "last line of defense".IVM Staff. "The Real Dad’s Army" , Imperial War Museum, Retrieved on 22 April 2015. On 27 September 1942, the minimum age for entry into the Home Guard was lowered to 16, provided that there was parental consent."THE 32ND STAFFORDSHIRE (ALDRIDGE) BATTALION 1940–1944: TIMELINE 1938–1945 – KEY DATES OF THE HOME GUARD" , Staffshomeguard.co.uk, Retrieved on 22 April 2015. The Secretary of State for War, Anthony Eden, called for men between the ages of 17 and 65 for Home Guard duty, so it was voluntarily undertaken by those of the younger age. Initially a poorly organized militia, the Home Guard and its young volunteers became well-equipped and well-trained. More than 1,200 Home Guard men died as a result of German bombings.

United States In World War II, the US only allowed men 18 years or older to be drafted or enlisted into the armed forces, although 17-year-olds were allowed to enlist with parental consent, and women were not allowed in armed conflict. Some successfully lied about their age. The youngest member of the United States military was 12-year-old Calvin Graham. He lied about his age when he enlisted in the US Navy, and his real age was not known until after he was wounded."Interesting Facts About World War II" , Armed Forces History Museum, Retrieved on 10 April 2015.

Poland From 1939, Polish youth created multiple resistance organisations. Children also joined military organisations despite the age limit, where they acted as liaison or distributor. Children also fought in extreme situations like Operation Tempest or Warsaw Uprising. In November 1942 age ranges were put in place: school of military support, 12 to 15 years; 16–18 years also in military support, Minor sabotage, Operation N, liaison office and reconnaissance; older had military training and joined Home Army. There were few well-known children aged below 14 who took part in military fights.

Legality