Encirclement is a military term for the situation when a force or target is isolated and surrounded by enemy forces. The German term for this is Kesselschlacht ("cauldron battle"); a comparable English term might be "in the bag".
This situation is highly dangerous for the encircled force: at the strategic level, because it cannot receive supplies or reinforcements, and on the tactical level, because the units in the force can be subject to an attack from several sides. Lastly, since the force cannot retreat, unless it is relieved or can break out, it must either fight to the death or surrender.
Encirclement has been used throughout the centuries by military leaders, including generals such as Alexander the Great, Khalid bin Waleed, Hannibal, Sun Tzu, Shaka Zulu, Wallenstein, Napoleon, Moltke, Heinz Guderian, von Rundstedt, von Manstein, Zhukov, and Patton. Sun Tzu suggests that an army should not be completely encircled, but should be given some room for escape, in order to prevent that 'encircled' army's men lifting their morale and fighting till the death –- a better situation would be them considering the possibility of a retreat. Examples of this might be the battles of Dunkirk, in 1940, and the Falaise Gap in 1944.
The main form of encircling, the "double pincer," is executed by attacks on the flanks of a battle, where the mobile forces of the era, such as light infantry, cavalry, tanks, or APCs attempt to force a breakthrough to utilize their speed to join behind the back of the enemy force, and complete the "ring", while the main enemy force is stalled by probing attacks. The encirclement of the German Sixth Army in the Battle of Stalingrad in 1942 is a typical example of this.
If there is a natural obstacle, such as ocean or mountains on one side of the battlefield, only one pincer is needed ("single pincer"), because the function of the second arm is taken over by the natural obstacle. The German attack into the lowlands of France in 1940 is a typical example of this.
A third and more rare type of encirclement can ensue from a breakthrough in an area of the enemy front, and exploiting that with mobile forces, diverging in two or more directions behind the enemy line. Full encirclement rarely follows this, but the threat of it severely hampers the defender's options. This type of attack pattern is centerpiece to Blitzkrieg operations. By the extreme difficulty of this operation, it can only be executed if the offensive force has a vast superiority, either in technology, organization, or sheer numbers. The Barbarossa campaign of 1941 saw some examples of this.
The danger to the encircling force is that it is, itself, cut off from its logistical base; if the encircled force is able to stand firm, or maintain a supply route, the encircling force can be thrown into confusion (for example, Rommel's "Dash to the Wire" in 1941) or be comprehensively destroyed (as during the Burma campaign, in 1944).
A special kind of encirclement is the siege. In this case, the encircled force voluntarily allows this to happen at a stronghold location where long-lasting supplies and defensive constructions or fortifications are in place, allowing them to repel attacks. Sieges have taken place in almost all eras of warfare.
Examples of battles of encirclement:
- Battle of Thermopylae (480 BC)
- Battle of Cannae (216 BC)
- Battle of Walaja (633 AD)
- Battle of Fraustadt (1706)
- Battle of Isandlwana (1879)
- Battle of Tannenberg (1914)
- Battle of Magdhaba (1916)
- Battle of Rafa (1916)
- First Battle of Gaza (1917)
- Battle of Beersheba (1917)
- Battle of Megiddo (1918)
- Battle of Suomussalmi (1939-1940)
- Battle of Kiev (1941)
- Battle of Smolensk (1941)
- Battle of Stalingrad (1942-1943)
- Battle of Misrata (2011)