Military reserve
Encyclopedia
A military reserve, tactical reserve, or strategic reserve (and normally called only as the/his/their "Reserve/(s)" or sometimes as a "reserve formation") is a group of military personnel or units which are initially not committed to a battle by their commander so that they are available to address unforeseen situations or exploit suddenly developing opportunities. Such forces may be held back to defend against attack from other enemy forces, to be committed to the existing battle if the enemy exposes a vulnerability, or to serve as relief for troops already fighting.
A military reserve is different from a military reserve force
, which is a military organization composed of military personnel who maintain their military skills and readiness in a long-term part-time commitment to support their country if needed. Military reserve refers to specific trained pre-organized forces operating as an on call basis from the main military force.
to ca. the sixth century BC, at least as far as the early Roman Legion
ary formations when their lines were organized with newer less qualified soldiers in the front ranks backed by a wily group of experienced veterans. Earning the right and having the experience to stand in the reserve or third rank was considered an achievement and promotion in the Roman culture.
On battlefields it was discovered that it was often better to have a group of soldiers held away from the line, to deal with weak points or opportunities, since it is very difficult for a unit or formation which is in action to extricate itself in good order and then refocus to the new assignment. This also causes the situation in the sector that unit was fighting in originally to become worse. By using uncommitted reserves the commander could continue his operations in all sectors and quickly move to reinforce weak points or exploit opportunities.
consisting of armoured and mechanised divisions
which are held in reserve with the purpose of exploiting a breakthrough or containing an enemy advance. Typically what is a reserve for one headquarters
is not the reserve for a higher headquarters
(though depending on the setup they may be). So if one of a battalion's companies is held is reserve during a battle, the company is considered to be a reserve for the battalion but not for the brigade or the division, since it is committed to action in its parent battalion sector. Similarly the British Reserve Army of World War I
and the American Fifteenth Army of World War II
were only reserves in their theater, as far as the national Headquarters was concerned, they were committed since they were not available to be sent for action in any other theater.
. In the event of reserves being sent forward to exploit a breakthrough, usually some are kept back to deal with any counterattack
. Reserves can also be employed to relieve troops, thus allowing for a rotation ensuring all troops get adequate rest.
Reserves may also exist in a global sense, as in instead of being tasked as the reserve in some area, units and formations may be held back as forces which could be sent to potential new hotspots, or held back for a decisive battle, as the battleship Yamato
was.
, ensuring that there would be no collapse, as well as in Italy, to speedily take over most of the country after the Allied landing and the Italian surrender. Conversely, the lack of reserves to deal with the Allied landings in Sicily compelled the Germans to move troops from the Eastern Front (which included units and formations then heavily engaged) causing the German offensive at Kursk to be adversely affected, and the fact that in the Battle of the Bulge
many of Germany's reserves had been expended, contributed heavily to the general German collapse in 1945.
In the aftermath of World War I
, the extensive colonial commitments of the United Kingdom
ensured that few battalions were available for the Anglo-Irish War, which decreased the British ability to deal with the crisis.
At the Battle of Gaugamela
, Alexander the Great's cavalry which had been held back, first dealt with outflanking movements of the Persians and later when a gap opened up broke through to win the battle.
of the British Expeditionary Force during the First World War
. Under the command of Lieutenant General
Sir Hubert Gough
, the Reserve Army was formed on 23 May 1916 prior to the Battle of the Somme
and was renamed the Fifth Army
in October of that year.
The intended purpose of the army was to carry out the breakthrough phase of the Somme offensive once General Sir Henry Rawlinson's Fourth Army
had captured the German front-line trenches. For this role Gough was provided with the three British cavalry
divisions and in June he was allocated an infantry corps
of three divisions to support the advance.
's III Corps is a dedicated counter-offensive corps.
A military reserve is different from a military reserve force
Military reserve force
A military reserve force is a military organization composed of citizens of a country who combine a military role or career with a civilian career. They are not normally kept under arms and their main role is to be available to fight when a nation mobilizes for total war or to defend against invasion...
, which is a military organization composed of military personnel who maintain their military skills and readiness in a long-term part-time commitment to support their country if needed. Military reserve refers to specific trained pre-organized forces operating as an on call basis from the main military force.
Background
In concept, the idea dates back in antiquityAncient history
Ancient history is the study of the written past from the beginning of recorded human history to the Early Middle Ages. The span of recorded history is roughly 5,000 years, with Cuneiform script, the oldest discovered form of coherent writing, from the protoliterate period around the 30th century BC...
to ca. the sixth century BC, at least as far as the early Roman Legion
Roman legion
A Roman legion normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. The organization of legions varied greatly over time but they were typically composed of perhaps 5,000 soldiers, divided into maniples and later into "cohorts"...
ary formations when their lines were organized with newer less qualified soldiers in the front ranks backed by a wily group of experienced veterans. Earning the right and having the experience to stand in the reserve or third rank was considered an achievement and promotion in the Roman culture.
On battlefields it was discovered that it was often better to have a group of soldiers held away from the line, to deal with weak points or opportunities, since it is very difficult for a unit or formation which is in action to extricate itself in good order and then refocus to the new assignment. This also causes the situation in the sector that unit was fighting in originally to become worse. By using uncommitted reserves the commander could continue his operations in all sectors and quickly move to reinforce weak points or exploit opportunities.
Reserves at various levels
In the modern battlefield, reserves exist at all levels, from a platoon held back from a company level engagement, to whole army corpsCorps
A corps is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service...
consisting of armoured and mechanised divisions
Division (military)
A division is a large military unit or formation usually consisting of between 10,000 and 20,000 soldiers. In most armies, a division is composed of several regiments or brigades, and in turn several divisions typically make up a corps...
which are held in reserve with the purpose of exploiting a breakthrough or containing an enemy advance. Typically what is a reserve for one headquarters
Headquarters
Headquarters denotes the location where most, if not all, of the important functions of an organization are coordinated. In the United States, the corporate headquarters represents the entity at the center or the top of a corporation taking full responsibility managing all business activities...
is not the reserve for a higher headquarters
Headquarters
Headquarters denotes the location where most, if not all, of the important functions of an organization are coordinated. In the United States, the corporate headquarters represents the entity at the center or the top of a corporation taking full responsibility managing all business activities...
(though depending on the setup they may be). So if one of a battalion's companies is held is reserve during a battle, the company is considered to be a reserve for the battalion but not for the brigade or the division, since it is committed to action in its parent battalion sector. Similarly the British Reserve Army of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
and the American Fifteenth Army of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
were only reserves in their theater, as far as the national Headquarters was concerned, they were committed since they were not available to be sent for action in any other theater.
Employment
The decision when and where and how to employ the reserves is one of the most important decisions a commander makes. Usually only a part of the reserves are utilised at any given time, since these are often sufficient to accomplish the task at hand. The "all reserves forward" order is given only in times of extreme crisis where it is clear the enemy will not be stopped otherwise. An example of this was on one of the days in the Battle of BritainBattle of Britain
The Battle of Britain is the name given to the World War II air campaign waged by the German Air Force against the United Kingdom during the summer and autumn of 1940...
. In the event of reserves being sent forward to exploit a breakthrough, usually some are kept back to deal with any counterattack
Counterattack
A counterattack is a tactic used in response against an attack. The term originates in military strategy. The general objective is to negate or thwart the advantage gained by the enemy in attack and the specific objectives are usually to regain lost ground or to destroy attacking enemy units.It is...
. Reserves can also be employed to relieve troops, thus allowing for a rotation ensuring all troops get adequate rest.
Reserves may also exist in a global sense, as in instead of being tasked as the reserve in some area, units and formations may be held back as forces which could be sent to potential new hotspots, or held back for a decisive battle, as the battleship Yamato
Japanese battleship Yamato
, named after the ancient Japanese Yamato Province, was the lead ship of the Yamato class of battleships that served with the Imperial Japanese Navy during World War II. She and her sister ship, Musashi, were the heaviest and most powerfully armed battleships ever constructed, displacing...
was.
Effect of reserves in history
Reserve troops (or lack thereof) have played a big role in battles and campaigns throughout history, especially in the twentieth century. The presence of reserves in France and southern Europe allowed Nazi Germany to quickly rush forces to Tunisia to deal with the aftermath of Operation TorchOperation Torch
Operation Torch was the British-American invasion of French North Africa in World War II during the North African Campaign, started on 8 November 1942....
, ensuring that there would be no collapse, as well as in Italy, to speedily take over most of the country after the Allied landing and the Italian surrender. Conversely, the lack of reserves to deal with the Allied landings in Sicily compelled the Germans to move troops from the Eastern Front (which included units and formations then heavily engaged) causing the German offensive at Kursk to be adversely affected, and the fact that in the Battle of the Bulge
Battle of the Bulge
The Battle of the Bulge was a major German offensive , launched toward the end of World War II through the densely forested Ardennes mountain region of Wallonia in Belgium, hence its French name , and France and...
many of Germany's reserves had been expended, contributed heavily to the general German collapse in 1945.
In the aftermath of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, the extensive colonial commitments of the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
ensured that few battalions were available for the Anglo-Irish War, which decreased the British ability to deal with the crisis.
At the Battle of Gaugamela
Battle of Gaugamela
The Battle of Gaugamela took place in 331 BC between Alexander the Great and Darius III of Persia. The battle, which is also called the Battle of Arbela, resulted in a massive victory for the ancient Macedonians and led to the fall of the Achaemenid Empire.-Location:Darius chose a flat, open plain...
, Alexander the Great's cavalry which had been held back, first dealt with outflanking movements of the Persians and later when a gap opened up broke through to win the battle.
British Reserve Army in World War I
The Reserve Army was a field armyArmy
An army An army An army (from Latin arma "arms, weapons" via Old French armée, "armed" (feminine), in the broadest sense, is the land-based military of a nation or state. It may also include other branches of the military such as the air force via means of aviation corps...
of the British Expeditionary Force during the First World War
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. Under the command of Lieutenant General
Lieutenant General
Lieutenant General is a military rank used in many countries. The rank traces its origins to the Middle Ages where the title of Lieutenant General was held by the second in command on the battlefield, who was normally subordinate to a Captain General....
Sir Hubert Gough
Hubert Gough
General Sir Hubert de la Poer Gough GCB, GCMG, KCVO was a senior officer in the British Army, who commanded the British Fifth Army from 1916 to 1918 during the First World War.-Family background:...
, the Reserve Army was formed on 23 May 1916 prior to the Battle of the Somme
Battle of the Somme (1916)
The Battle of the Somme , also known as the Somme Offensive, took place during the First World War between 1 July and 14 November 1916 in the Somme department of France, on both banks of the river of the same name...
and was renamed the Fifth Army
British Fifth Army
The Fifth Army was a field army of the British Army during World War I and part of the British Expeditionary Force during the First World War.-History:...
in October of that year.
The intended purpose of the army was to carry out the breakthrough phase of the Somme offensive once General Sir Henry Rawlinson's Fourth Army
British Fourth Army
The Fourth Army was a field army that formed part of the British Expeditionary Force during the First World War. The Fourth Army was formed on 5 February 1916 under the command of General Sir Henry Rawlinson to carry out the main British contribution to the Battle of the Somme.-History:The Fourth...
had captured the German front-line trenches. For this role Gough was provided with the three British cavalry
Cavalry
Cavalry or horsemen were soldiers or warriors who fought mounted on horseback. Cavalry were historically the third oldest and the most mobile of the combat arms...
divisions and in June he was allocated an infantry corps
Corps
A corps is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service...
of three divisions to support the advance.
American III Corps
The United States ArmyUnited States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
's III Corps is a dedicated counter-offensive corps.
Strike Corps
Some armour heavy formations of India and Pakistan are designated as "strike corps" to take advantage of breakthroughs.See also
- Military reserve forceMilitary reserve forceA military reserve force is a military organization composed of citizens of a country who combine a military role or career with a civilian career. They are not normally kept under arms and their main role is to be available to fight when a nation mobilizes for total war or to defend against invasion...
- Reserve Component of the Armed Forces of the United States