BPSC 71st CCE Prelims General Studies · Question 104 of 150

Correct — B, Kra Isthmuses (the booklet prints 'Isthmuses' in the plural on all four options). The Kra Isthmus, or Isthmus of Kra, is the narrowest part of the Malay Peninsula — about 44 km across at its slimmest, between Kra Buri in Ranong province and Chumphon in southern Thailand — with the Andaman Sea on its western flank and the Gulf of Thailand on its east. That geography is well documented and it is what makes this option the right one. The nickname is a different matter, and this card will not pretend otherwise: 'Devil's Neck' is the label the Commission's key requires and it circulates widely in Indian exam material, but it is not attested in standard geographical references, so treat it as an exam label attached to the Kra Isthmus rather than as established geographical usage — and answer the question from the geography, which decides it cleanly. Of the four isthmuses listed, the Kra is the only one that still throttles world shipping. Everything sailing between the Indian Ocean and East Asia has to run the long way round the Malay Peninsula and squeeze through the Strait of Malacca; a canal cut across the 44 km neck at Kra would let ships bypass Malacca altogether. That is why the proposal has been alive for more than three centuries, was reported to the British Parliament in 1859 by Consul Robert Schomburgk, and is still argued over today as the Thai Canal or Kra Canal — and why it has still never been built. UPSC tested precisely this in Prelims 2011, where the only correct statement of two was that a new canal across the Kra isthmus between the Gulf of Siam and the Andaman Sea would greatly reduce navigation time and distance between India and East Asia. Every other isthmus on this list has either already been cut by a canal — Panama in 1914, Corinth in 1893 — or does not separate two seas at all, which is Karelia's case. The uncut, strategically pinched neck is Kra.

• (a)Isthmuses of Panama — The default guess, because Panama is the most famous isthmus in the world: the narrow strip between the Caribbean Sea and the Pacific Ocean that links North and South America and is thought to have closed about 3 million years ago, reshaping ocean currents and global climate. But it stopped being a chokepoint in 1914 — the 82 km Panama Canal, with three lock systems in all — Gatun at the Atlantic end, Pedro Miguel and Miraflores at the Pacific end, was formally opened on 15 August 1914 with the passage of the SS Ancon, and a wider third lane was added between 2007 and 2016.
• (c)Karelian Isthmuses — The Karelian Isthmus, 45–110 km wide, lies between the Gulf of Finland and Lake Ladoga in north-western Russia — so it separates a sea arm from a lake, not two seas, and no ocean trade route has ever run near it. Its fame is military rather than maritime: Finland's Mannerheim Line ran across it, the Soviet advance broke through only in February 1940, and Finland ceded most of it under the Peace of Moscow of 12 March 1940.
• (d)Isthmuses of Corinth — The sharpest trap on the list, because Corinth is far narrower than Kra — only 6.3 km at its narrowest — joining the Peloponnese to mainland Greece with the Gulf of Corinth on the west and the Saronic Gulf on the east. A candidate reasoning that the narrowest neck must be the 'Devil's Neck' lands here. But it was cut long ago: the ancient Diolkos stone ramp dragged ships across it, and the Corinth Canal was completed in 1893 after eleven years' work. It carries small vessels and tourist traffic, not world trade.

An isthmus is a narrow neck of land that joins two larger land masses and, in doing so, separates two water bodies — the exact mirror image of a strait, which is a narrow neck of water joining two water bodies and separating two land masses. Because an isthmus stands in the way of shipping, the history of every important one is the history of an attempt to cut through it. Three of the world's great isthmuses now carry canals: Suez, cut in 1869 across the Isthmus of Suez between the Mediterranean and the Red Sea; Panama, opened in 1914 between the Caribbean and the Pacific; and Corinth, completed in 1893 across the neck that ties the Peloponnese to Greece. The Kra is the great uncut one — the narrowest point of the Malay Peninsula, dividing the Andaman Sea from the Gulf of Thailand, and therefore the last major land barrier still forcing a long maritime detour. Other isthmuses worth knowing are Tehuantepec in southern Mexico and the Karelian Isthmus between the Gulf of Finland and Lake Ladoga, the latter a land bridge between a sea and a lake rather than between two seas.

The honest way to reason through this question is to set the nickname aside, because it cannot be checked against any standard geographical source, and to ask instead which of the four necks behaves like a strangled throat for shipping. Panama and Corinth have both been cut by canals, in 1914 and 1893 respectively, so neither obstructs anything any more. The Karelian Isthmus lies between the Gulf of Finland and a lake, so it never obstructed ocean trade at all; its significance is the Mannerheim Line and the Winter War. That leaves the Kra Isthmus, which is still solid land, still only about 44 km wide, and still the reason every ship moving between the Indian Ocean and East Asia has to round the Malay Peninsula and thread the Strait of Malacca — a long, narrow, congested passage whose vulnerability is discussed in strategic writing as the 'Malacca dilemma'. Cutting Kra would end that detour, which is why the plan has been raised, costed and shelved repeatedly since the seventeenth century. The single fact that discriminates: the isthmus separating the Andaman Sea from the Gulf of Thailand is Kra, and it is the only one of the four with no canal through it.

• The Kra Isthmus is the narrowest part of the Malay Peninsula — about 44 km at its narrowest, between Kra Buri (Ranong province) and Chumphon in southern Thailand.
• It separates the Andaman Sea, on the Indian Ocean side, from the Gulf of Thailand on the Pacific side; a canal here would let shipping bypass the Strait of Malacca entirely.
• A Kra or Thai Canal has been discussed for more than 300 years and was reported to the British Parliament in 1859 by Consul Robert Schomburgk; it has never been built, and UPSC Prelims 2011 asked about exactly this proposal.
• The nickname 'Devil's Neck' used in this question is carried by Indian exam sources and by the Commission's key, but it is not attested in standard geographical references — learn the geography, not the label.
• The three distractor isthmuses in figures: Panama (Caribbean–Pacific, canal 82 km, opened 15 August 1914); Corinth (6.3 km wide, canal completed 1893, ancient Diolkos ship-ramp); Karelian (45–110 km wide, Gulf of Finland to Lake Ladoga, Mannerheim Line, ceded to the USSR on 12 March 1940).

• Picking Corinth because it is the narrowest of the four; narrowness alone does not make a chokepoint, and Corinth was cut in 1893
• Picking Panama out of familiarity — it is the most famous isthmus but has carried a canal since 1914
• Treating 'Devil's Neck' as a standard geographical name. It is exam-book usage; the checkable facts are the 44 km width and the Andaman Sea–Gulf of Thailand separation

BPSC asks for the label — which isthmus is 'known as' something — so the mark turns on having met a nickname, not on understanding the place. UPSC asks the consequence instead: in 2011 it wanted to know whether a canal across the Kra isthmus would shorten navigation between India and East Asia, and in 2007 which country planned a rival to the Panama Canal. Learn what an isthmus does and both styles are covered; learn only nicknames and only one is.

• practice — not a real PYQ

  The Kra Isthmus separates which two water bodies?

  • (a)Andaman Sea and Gulf of Thailand
  • (b)South China Sea and Java Sea
  • (c)Bay of Bengal and Arabian Sea
  • (d)Gulf of Tonkin and Sulu Sea

  Answer(a) Andaman Sea and Gulf of Thailand — the isthmus is the narrowest part of the Malay Peninsula, about 44 km across, in southern Thailand.

• practice — not a real PYQ

  The Corinth Canal, completed in 1893, cuts across the isthmus that joins the Peloponnese to the mainland of which country?

  • (a)Italy
  • (b)Greece
  • (c)Turkey
  • (d)Spain

  Answer(b) Greece — the Isthmus of Corinth is 6.3 km wide, with the Gulf of Corinth to its west and the Saronic Gulf to its east.