Encirclement is a military term for the situation when a force or target is isolated and surrounded by enemy forces. The situation is highly dangerous for the encircled force. At the strategic level, it cannot receive supplies or reinforcements, and on the tactical level, 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 fight to the death or surrender. A special kind of encirclement is the siege. In that case, the encircled forces are enveloped in a fortified position in which long-lasting supplies and strong defences are in place, allowing them to withstand attacks. Sieges have taken place in almost all eras of warfare. History Encirclement has been used throughout the centuries by military leaders, including generals such as Spartacus, Alexander the Great, Julius Caesar, Genghis Khan, Khalid bin Waleed, Hannibal, Sun Tzu, Yi Sun Shin, Shaka Zulu, von Wallenstein, Nader Shah, Napoleon, von Moltke, Heinz Guderian, von Rundstedt, von Manstein, Zhukov, Patton and Soleimani. Sun Tzu and other military thinkers suggest that an army should be not completely encircled but instead given some room for escape. Otherwise, the "encircled" army's men will lift their morale and fight to the death. It is better to have them consider the possibility of a retreat. Once the enemy retreats, it can be pursued and captured or destroyed with far less risk to the pursuing forces than a fight to the death. Types of encirclement The main form of encircling, the "double pincer", is executed by attacks on the flanks of a battle whose mobile forces of the era, such as light infantry, cavalry, tanks, or armoured personnel carriers 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. During the Winter War, Finland used "pocket tactics" against the Soviet Union, called motti; in the context of war, motti describes a tactic that the Finns used to immobilise, segment, surround and destroy the Soviet troops that were many times as large as them. If there is a natural obstacle, such as ocean or mountains on one side of the battlefield, only one