Pentomic Division

In the mid-1950s, the command of the US Armed Forces developed a strategy of massive retaliation . The essence of the strategy of massive retaliation is that the state, in the event of aggression against it, reserves the right to disproportionate use of force against the aggressor. Such a strategy works on the principle of mutually guaranteed destruction, with the only difference being that a retaliatory nuclear strike will follow even in the event of an attack using conventional weapons or a local border conflict ^[2] . The term “massive retaliation” was first mentioned by American diplomat John Dulles on January 12, 1954.

Based on the new strategy, the American command concluded that it was necessary to increase the mobility of ground forces. According to the new concept, the classical ternary organization of troops, in which each combat unit has three units of the same type of the lower level, was recognized as irrational and a new organization was introduced. According to the new organization called the "Pentomic Division", the regimental unit was abolished in all infantry divisions. Instead of the 3 infantry regiments , which previously formed the basis of the division , 5 infantry fighting groups , a tank battalion and divisional artillery were created. The latter included Honest John unguided tactical missiles and 203.2mm howitzers as a means of delivering nuclear weapons to targets. In fact, infantry divisions were armed with nuclear weapons.

As a result of the transformations, the personnel of the infantry divisions was significantly reduced, and the firepower increased due to the introduction of nuclear weapons. Similar reforms were carried out in the US airborne divisions .

In practice, the following shortcomings in the pentomic structure of the divisions were found out ^[3] :

• difficulty in retraining officers when promoted, because there were no intermediate command posts between company commanders (position for an officer with the rank of captain ) and commanders of battle groups (position for colonel ). The situation was complicated by the quick retirement of officers who had combat experience gained in World War II and the Korean War ;
• difficulty in managing a large number of units. With a pentamic structure in the battle group there were up to 5-7 companies , which in combat conditions were strengthened from 2 to 4 units of various branches of the army (engineering, artillery, etc.);
• loss of regimental traditions: pre-existing infantry regiments, which had a long history, had cohesion of personnel. Under pentomic divisions, battle groups were an infantry formation randomly assembled from different regiments of the division. At the same time, the cohesion of the personnel and elements of previously acquired combat coordination were lost.
• loss of command: with the pentomic structure, the battalion command was abolished, which was commanded by officers in the US army with the rank of major and lieutenant colonel .

The main drawback of infantry divisions in terms of their pentomic structure was the inability to conduct effective military operations without the use of nuclear weapons. In 1961, a Flexible Response strategy was adopted, which considered the conduct of war using both nuclear weapons and conventional weapons. US Army Command was forced to abandon the pentomic divisions. Since 1962, new division states were introduced. By July 1964, all US Army divisions (armored, airborne, mechanized, and infantry) were transferred to new states ^{[1] [4] [3]} . The brigade organization was taken for the new division structure ^[5] .

A similar structure called the , which existed between 1960 and 1965, was introduced in the ground forces of Australia . Due to structural deficiencies similar to those encountered in the United States, a return was made to the previous troop organization ^[6] .

In the Turkish army, the pentomic structure existed from 1960 to 1964.

In the ground forces of Germany, the pentomic structure was introduced in 1957 and lasted several years ^[7] .

In the ground forces of Spain in 1958, as an experiment, 3 pentomic infantry divisions were created. By 1960, their number had grown to 8 divisions. In 1965, a return was made from the pentomic structure to the classical one ^[8] .

• "The Pentomic Era." - Washington: National Defense Universty Press, 1986. - 205 p.