Soviet military doctrine
Soviet military doctrine distinguishes several sizes of encirclement:
- Cauldron or kettle (Russian: котёл, translit. kotyol or kotel): a very large, strategic-level concentration of trapped enemy forces
- Sack (Russian: мешок, translit. meshok): an operational-level trapped enemy force
- Nest (Russian: гнездо, translit. gnezdo): a tactical-level trapped enemy force
The significance of these terms are reflected by the conception of what can be expected in combat in encirclement operations. A cauldron is expected to be "boiling" with combat activity, the large enemy forces still quite able to offer "hot" resistance in the initial stages of encirclement, and so are to be contained, but not engaged directly. A sack in Soviet experience was often created as a result of operational breakthroughs, and was sometimes as unexpected for the Soviet command as for the enemy. This encirclement, sometimes of an entity of unknown size, tended to move for some time after the initial encirclement due to inherently dynamic nature of operational warfare. By contrast a nest was a reference to a tactical, well-defined and contained encirclement of enemy troops that was seen as a fragile construct of enemy troops unsupported by its parent formation (the use of the word nest is similar to the more familiar English expression machine gun nest).
In German the word Kessel (literally a cauldron) is commonly used to refer to an encircled military force, and a Kesselschlacht (cauldron battle) refers to a pincer movement. The common tactic which would leave a Kessel is referred to Keil and Kessel (Keil means wedge). The term is sometimes borrowed for use in English texts about World War II. Another use of Kessel is to refer to Kessel fever, the panic and hopelessness felt by any troops who were surrounded with little or no chance of escape. Examples of Kessel battles are:
Also, during the Battle of Arnhem, the Germans referred to the pocket of trapped British Paratroops as the Hexenkessel (lit. The Witches' Cauldron).
In Spanish the word Cerco (literally a fence or siege) is commonly used to refer to an encircling military force. Cercos were particularly common in the Chaco War between Bolivia and Paraguay (1932–1935) and encirclement battles were decisive for the outcome of the war. In the Campo Vía pocket 7,500 Bolivians were taken prisoner out of an initial combat force of 10,000. Other cercos of the war include the battle of Campo Grande and the battle of Cañada Strongest.
Motti is Finnish military slang for a totally encircled enemy unit. The tactic of encircling it is called motitus, literally meaning the formation of an isolated block or "motti", but in effect meaning an entrapment or envelopment.
The word means "mug" in many Finnish dialects; an alternate translation refers to a cubic meter of firewood, a relatively small area in which an encircled enemy could be "cut down" like trees. motti is thus related to kessel. A motti in military tactics therefore means the formation of "bite sized" enemy units which are easier to contain and deal with.
This tactic of envelopment was used extensively by the Finnish forces in the Winter War and the Continuation War to good effect. It was especially effective against some of the mechanized units of the Soviet Army, which were effectively restricted to the long and narrow forest roads with virtually no way other than forwards or backwards. Once committed to a road, the Soviet troops effectively were trapped. Unlike the mechanized units of the Soviets, the Finnish troops could move quickly through the forests on skis and break columns of armoured Soviet units into smaller chunks (e.g., by felling trees along the road). Once the large column was split up into smaller armoured units, the Finnish forces attacking from within the forest could strike the weakened column. The smaller pockets of enemy troops could then be dealt with individually by concentrating forces on all sides against the entrapped unit.
A motitus is therefore a double envelopment manoeuvre, using the ability of light troops to travel over rough ground to encircle enemy troops on a road. Heavily outnumbered but mobile forces could easily immobilize an enemy many times more numerous.
By cutting the enemy columns or units into smaller groups and then encircling them with light and mobile forces, such as ski-troops during winter a smaller force can overwhelm a much larger force. If the encircled enemy unit was too strong, or if attacking it would have entailed an unacceptably high cost, e.g., because of a lack of heavy equipment, the motti was usually left to "stew" until it ran out of food, fuel, supplies, and ammunition and was weakened enough to be eliminated. Some of the larger mottis held out until the end of the war because they were resupplied by air. Being trapped, these units were therefore not available for battle operations.
The largest motti battles in the Winter War occurred at the Battle of Suomussalmi. Three Finnish regiments enveloped and destroyed two Soviet divisions as well as a tank brigade trapped on a road.