# Interior lines > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Interior_lines > Markdown URL: https://mediated.wiki/source/Interior_lines.md > Source: https://en.wikipedia.org/wiki/Interior_lines > Source revision: 1356228942 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Method of movement and operation in warfare **Interior lines**[a] (as opposed to **exterior lines**) is a [military term](/source/Military_terminology), derived from the generic term *line of operation* or *line of movement*.[1] The term "interior lines" is commonly used to illustrate, describe, and analyze the various possible routes (lines) of logistics, supply, reconnaissance, approach, attack, evasion, maneuver, or retreat of armed forces. Interior line strategies are based on the fact that lines of movement and communication within an enclosed area are shorter and safer than those on the outside. As the area held by a defensive force shrinks, the interior line advantage held by the defensive force increases.[2][3] Skillful and comprehensive application of interior line tactics can, for a partially surrounded combat force, provide vital breathing space, greatly reduce time, effort, security, and secrecy of resupplies and redeployment, and decrease the number of casualties. These effects may have a great impact on morale and eventually prove decisive, as according to [Napoleon Bonaparte](/source/Napoleon_Bonaparte): *"in war morale forces are to physical three to one"*.[4][5] ## Tactic By September 1950, US and South Korean Forces had been forced back to form the Pusan Perimeter in the South-East of [the peninsula](/source/Korean_Peninsula), giving the defenders shorter interior lines. This created a concentration of forces in defense, [allowing quicker reinforcements and logistics](/source/Battle_of_Pusan_Perimeter_logistics). Fresh troops and supplies were increasingly being brought into the port in [Pusan](/source/Busan), strengthening the defense even further and preventing a North Korean victory. By contrast, the North Korean supply line had lengthened, making offensive action harder to maintain. In the context of battlefield tactics, interior lines allow for more rapid concentration of resources (firepower and manpower) and afford greater tactical flexibility. Resources are ideally brought to bear at a point where the adversary is not able to quickly respond, because of their longer external lines. Examples include: - At the [Battle of Dyrrhachium (48 BC)](/source/Battle_of_Dyrrhachium_(48_BC)), the numerically superior [Optimates](/source/Optimates), led by [Gnaeus Pompeius Magnus](/source/Gnaeus_Pompeius_Magnus), defeated the more battle-hardened [Populares](/source/Populares), led by [Gaius Julius Caesar](/source/Gaius_Julius_Caesar), when Caesar attempted to encircle them. - During the [Battles of Lexington and Concord](/source/Battles_of_Lexington_and_Concord), [Brigadier General](/source/Brigadier_General) [Hugh Percy](/source/Hugh_Percy%2C_2nd_Duke_of_Northumberland) utilized interior lines during the British retreat, as his men were often surrounded by [militia](/source/Minutemen). - At the [Battle of Jena-Auerstedt](/source/Battle_of_Jena-Auerstedt), [Louis Nicolas Davout](/source/Louis_Nicolas_Davout) employed interior lines to defeat the main [Prussian army](/source/Prussian_army). - At the [Battle of Wagram](/source/Battle_of_Wagram), the [French](/source/First_French_Empire) under [Napoleon I](/source/Napoleon_I) defeated the Austrians by using interior lines to achieve [local numerical superiority](/source/Defeat_in_detail). - [George Gordon Meade](/source/George_Gordon_Meade) used interior lines against [Robert E. Lee](/source/Robert_E._Lee) at the [Battle of Gettysburg](/source/Battle_of_Gettysburg) in 1863.[6] ## Strategy As a strategy, interior lines are commonly employed to cut armies off from reinforcements and supplies, or prevent allies from uniting their forces. Interior lines often allow for a numerically inferior force to gain a numerical superiority over an adversary in a given locality, which increases the chances of overpowering an enemy and defeating it in detail. In overpowering an enemy locally, an army hopes to demoralize the enemy sufficiently to bring it to political terms. Some examples include: After the [Battle of Mondovi](/source/Battle_of_Mondovi), the French gained the advantage of having the interior position over their adversaries in the [First Coalition](/source/First_Coalition). - At the [Battle of Montenotte](/source/Battle_of_Montenotte), the [First French Republic](/source/First_French_Republic) under [Napoleon](/source/Napoleon_Bonaparte) defeated the [Austrians](/source/Habsburg_monarchy) and destroyed an entire corps, thereby destroying the link between the Austrians and their allies, the [Kingdom of Sardinia](/source/Kingdom_of_Sardinia). As a result of the victory, the Sardinians were separated from Austria and were unable to defeat the French or rejoin the Austrians. They eventually sued for peace. - [Frederick the Great's](/source/Frederick_II_of_Prussia) operational strategy, in his prosecution of the [Seven Years' War](/source/Seven_Years'_War) against the separate armies of the French, the Russians and the Austrians, can be considered an example of the advantage of interior lines in warfare. - Interior lines also gave the [Reds](/source/Red_Army) a distinct advantage over the [Whites](/source/White_movement) in the [Russian Civil War](/source/Russian_Civil_War). - [General](/source/General_(CSA)) [Robert E. Lee](/source/Robert_E._Lee) used interior lines during the [Battle of Antietam](/source/Battle_of_Antietam) during the [American Civil War](/source/American_Civil_War) in 1862.[7] - Though the [Pusan Perimeter](/source/Battle_of_Pusan_Perimeter) (Korea, 1950) was not an intentional strategy, the concentration of UN forces within the Perimeter allowed quick movement of supplies and reinforcements via interior lines. ## See also - [Military strategy](/source/Military_strategy) - [Two-front war](/source/Two-front_war) - [Encirclement](/source/Encirclement) ## Notes **Footnotes** 1. **[^](#cite_ref-1)** a term invented by 19th century Swiss-French officer and prominent author [Antoine-Henri Jomini](/source/Antoine-Henri_Jomini) ## References 1. **[^](#cite_ref-2)** Michael D. Lundy (December 6, 2017). ["Operations, chapter 5 - Passage of lines"](https://fas.org/irp/doddir/army/fm3-0.pdf) (PDF). US Army. Retrieved May 4, 2020. 1. **[^](#cite_ref-Morris1895_3-0)** William O'Connor Morris (1895). [*Moltke a biographical and critical study*](https://books.google.com/books?id=Cb8GAwAAQBAJ&pg=PA85). Рипол Классик. pp. 85–. [ISBN](/source/ISBN_(identifier)) [978-5-87074-092-8](https://en.wikipedia.org/wiki/Special:BookSources/978-5-87074-092-8). {{[cite book](https://en.wikipedia.org/wiki/Template:Cite_book)}}: ISBN / Date incompatibility ([help](https://en.wikipedia.org/wiki/Help:CS1_errors#invalid_isbn_date)) 1. **[^](#cite_ref-Burne1946_4-0)** Alfred Higgins Burne (1946). [*Strategy as Exemplified in the Second World War: A Strategical Examination of the Land Operations*](https://books.google.com/books?id=axo9AAAAIAAJ&pg=PA17). CUP Archive. pp. 17–. GGKEY:7F20S7AZG5P. 1. **[^](#cite_ref-5)** [*A General Biographical Dictionary: Comprising a Summary Account of the Most Distinguished Persons of All Ages, Nations, and Professions, Including More Than One Thousand Articles of American Biography ...*](https://books.google.com/books?id=j1E4AQAAMAAJ&pg=PA1001) A.V. Blake. 1845. pp. 1001–. 1. **[^](#cite_ref-Zabecki2006_6-0)** David T. Zabecki (27 September 2006). [*The German 1918 Offensives: A Case Study in The Operational Level of War*](https://books.google.com/books?id=4b9_AgAAQBAJ&pg=PP66). Routledge. pp. 66–. [ISBN](/source/ISBN_(identifier)) [978-1-134-25224-4](https://en.wikipedia.org/wiki/Special:BookSources/978-1-134-25224-4). 1. **[^](#cite_ref-Esq.2011_7-0)** Kent Masterson Brown, Esq. (1 August 2011). [*Retreat from Gettysburg: Lee, Logistics, and the Pennsylvania Campaign*](https://books.google.com/books?id=1L9RtUE9LhwC&pg=PA44). UNC Press Books. pp. 44–. [ISBN](/source/ISBN_(identifier)) [978-0-8078-6942-0](https://en.wikipedia.org/wiki/Special:BookSources/978-0-8078-6942-0). 1. **[^](#cite_ref-Dougherty2015_8-0)** Kevin Dougherty (6 March 2015). [*The Vicksburg Campaign: Strategy, Battles and Key Figures*](https://books.google.com/books?id=64X2BgAAQBAJ&pg=PA107). McFarland. pp. 107–. [ISBN](/source/ISBN_(identifier)) [978-1-4766-1993-4](https://en.wikipedia.org/wiki/Special:BookSources/978-1-4766-1993-4). --- Adapted from the Wikipedia article [Interior lines](https://en.wikipedia.org/wiki/Interior_lines) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Interior_lines?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.