The boundary lines may be national as well as international depending on the type of administrative territories they’re separating. While most of the important boundary lines are heavily guarded to ensure that the security rights of the country’s native people are protected, some of them are mere demarcations that encourage the unrestricted movement of people from one country to another. For example, the citizens of the Schengen Area are governed by a common administrative body – the European Union. This area includes 26 adjacent West European countries with no typical border controls among them.

Important boundary lines of India

India is the largest global democracy that shares its land borders with seven different countries, two of these nations – Pakistan and Bangladesh to the west and east respectively, once used to be a portion of the Indian subcontinent. The five other nations with whom the landmass of India is connected are Bhutan, Nepal, Myanmar, China, and Afghanistan. The land boundaries of India stretch to a massive length of 15,106 km. Indian navy also surveillances its maritime boundaries with the Maldives and Sri Lanka. 

The important boundary lines of India are discussed below:

1. Radcliffe Line: On 17th August 1947, the landmass of British India was divided into two independent nations as per the stipulation of boundary commissions of the Parliament of the United Kingdom. Cyril Radcliffe segregated the western part of Punjab as an independent Muslim nation – West Pakistan. At the same time, Bengal province was also divided and its significant eastern portion was allotted to East Pakistan. At present, this Radcliffe line serves both as the international boundary between India and Pakistan in the northwest frontier as well as the India – Bangladesh border in the east. 
2. Line of Control: This is one of the most critical boundary lines that remains heavily guarded throughout the year. It acts as the demarcation limit between the Jammu and Kashmir state of India and Pakistan occupied Kashmir. Though the whole of Jammu and Kashmir belongs to India, this border was formed as an outcome of the Shimla Agreement of 1972. It is not considered an international boundary. 
3. Line of Actual Control: This borderline separates the Indian state of Jammu and Kashmir from Aksai Chin. The Chinese Government annexed a portion of Kashmir under the Indo-China war of 1962. The Instrument of Accession denies the actuality of Aksai Chin, thus this hostile demarcation is not considered as an international border. 
4. McMahon Line: This frontier separates Tibet from the northeastern states of India since 1914. Lieutenant McMahon proposed this demarcation among Tibet, China, and the British Indian state of Assam during the contemporary Shimla Convention. Till today there remain disputes between China and India regarding the authenticity of the McMahon Line as the former does not recognize Tibet as a sovereign state. 
5. Durand Line: A minute section of this mutual demarcation line between India and Afghanistan remains to exist after Pakistan inherits Kashmir. This boundary was established in 1893 after the Second Anglo-Afghan War. Currently, it runs into China – Afghanistan border in the east and Iran – the Afghanistan border in the west. 

Important International Boundary Lines 

After a thorough survey of the critical Indian borders, now let us shift our focus to important boundary lines all across the world. 

Oder Neisse Line – After securing victory in the Second World War, the Allied Powers designed this boundary along the Oder and Neisse rivers separating Poland from Germany. Large sections of German territories were incorporated within the Polish administrative zone. 

38th Parallel: This latitudinal demarcation in the northern hemisphere is identified as a high-tension zone. It separates South Korea from North Korea since the end of the Second World War. At the Potsdam convention, this line was declared as a temporary demarcation by the military planners of both the US and the USSR army. Later on, the Cold War scenarios solemnized the separation of South Korea from North Korea under the leadership of Syngman Rhee who was against communist ideologies. 

Mason and Dixon Line: We may consider this as one of the important boundary lines across American provinces. It divides the United States of America into northern and southern halves. The adjacent states which share the border are Pennsylvania, Maryland, West Virginia, and Delaware. This artificial border which was intended to settle disputes among the British colonies of Delaware and Maryland still portrays many issues due to confusing legal arguments. 

49th Parallel: This boundary separates the British Columbia provinces of Canada from America. It also makes Alaska a part of the United States of America. In 1846, the Oregon Treaty recognized these important international boundary lines. 

Blue Line: Though not considered as an international boundary, it still separates Lebanon from Israel on the political map since 7th June 2000. The United Nations enforced this border into action to stop further interference of the Israeli army in Lebanese territory. 

Conclusion 

Important boundary lines have been protected by the armies since their inception to maintain the peace and prosperity of the nations concerned. Though the world had witnessed numerous brutal wars when treaties were breached following partial annexation of sovereign states, still the chaos was mediated by peace enforcing global bodies from time to time.