At the narrowest point of the Malay Peninsula, southern Thailand is only about 44 kilometers wide from the Andaman Sea to the Gulf of Thailand. Since 1677, the idea of digging a canal across this strip of land has repeatedly surfaced and faded throughout Thai history.
The proposed canal would connect the Indian Ocean with the South China Sea without passing through the Strait of Malacca. Yet despite centuries of discussion, it has never been built.
The obstacle has never been just the cost. According to a study by Ian Storey of the ISEAS-Yusof Ishak Institute, critics of the project have raised a more fundamental concern. A canal would physically divide Thailand into two separate landmasses.
It could also fuel separatism in the country's Malay-Muslim majority southern provinces, a region that has experienced decades of unrest.
For more than 300 years, eight Thai kingdoms and governments have revisited the proposal. They commissioned feasibility studies, then ultimately abandoned the project. Here is the story of the canal, from its origins in the 17th century to its latest revival attempts after 2014.
An Idea Repeatedly Blocked by Colonial Powers
The idea of excavating the Kra Isthmus was first considered in 1677 during the reign of King Narai. It resurfaced in 1793 when the younger brother of King Rama I proposed it for naval defense purposes.
The project did not receive serious attention until the 19th century. Even then, the interest came not from Thailand itself, but from two competing colonial powers, Britain and France.
Britain conducted surveys in 1843, 1849, 1863, and 1872. The studies concluded that both a canal and a railway across the isthmus were technically feasible. However, the projected costs were considered too high.
In 1883, French naval officer Bertrand-François Mahé de La Bourdonnais promoted the canal to strengthen French commercial interests in Indochina. He hoped it would allow Saigon to compete with British-controlled Singapore.
Britain, determined to protect its commercial interests on the Malay Peninsula, strongly opposed the proposal. It even compelled the Kingdom of Siam to sign treaties in 1897 and again in 1946. Both agreements prohibited the construction of an interoceanic canal within Siamese territory.
Cold War-Era Feasibility Studies
The project returned to serious discussion in 1972. Chinese-Thai industrialist K.Y. Chow funded a US$400,000 feasibility study by the American consulting firm Tippetts-Abbett-McCarthy-Stratton (TAMS).
After evaluating nine possible routes, TAMS recommended Route 5A. The proposal called for a 102-kilometer canal linking Satun on the west coast with Songkhla on the east coast. Construction was estimated to take 12 years and cost US$5.6 billion.
The study also suggested an alternative scenario. If small-scale nuclear explosions were used for excavation, the project could be completed in 10 years at a cost of US$3.5 billion.
However, shortly after the TAMS report was completed, the 1973 Oil Crisis struck. The project was shelved once again.
Throughout the 1970s and 1980s, Japan expressed interest in financing the canal. The country relied heavily on the Strait of Malacca for energy imports from the Middle East.
In the mid-1980s, the Mitsubishi Research Institute even revisited the nuclear excavation option proposed in the TAMS study. Nevertheless, none of these plans ever moved beyond the planning stage.
Thaksin-Era Ambitions That Collapsed
The Kra Canal returned to the national agenda in the early 2000s under the government of Thaksin Shinawatra. At the time, Deputy Prime Minister and Defense Minister Chavalit Yongchaiyudh led the initiative.
The retired general had previously served as Thailand's military liaison with China during the Cambodian Crisis of the 1980s. He claimed that China was among the countries interested in financing the project.
A new feasibility study was commissioned. However, within a few years, the project collapsed amid allegations of financial mismanagement.
In 2005, Thaksin proposed a less expensive alternative. Instead of a canal, he suggested building an oil pipeline across the Kra Isthmus. That proposal also came to an end after he was overthrown in the 2006 military coup.
The Post-2014 Revival and Fears of Division
Following the 2014 military coup, the Kra Canal proposal resurfaced through two advocacy groups: the Thai-Chinese Culture and Economic Association (TCCEA) and the Thai Canal Association for Study and Development (TCASD).
In 2015, the TCCEA promoted Route 5A. The group estimated that the canal could be built within eight years at a cost of US$20 billion.
In the same year, the Asia Union Group led by Chavalit signed a memorandum of understanding with the Chinese firm China-Thailand Kra Infrastructure Investment and Development Company. However, both the Thai and Chinese governments denied any official involvement in the agreement.
In 2017, the TCASD, led by retired General Pongthep Tesprateep, proposed a new alignment known as Route 9A. The plan called for a 120-kilometer canal connecting Krabi and Nakhon Si Thammarat. It was also linked to the US$40 billion Eastern Economic Corridor project.
King Vajiralongkorn, who ascended the throne in December 2016 and was formally crowned in May 2019 at the age of 64, was seen by some supporters as having the opportunity to leave a lasting legacy through the project. He became the oldest monarch to ascend the throne in the Chakri dynasty.
However, as noted in the ISEAS study published in September 2019, he never publicly commented on the canal. Prime Minister Prayut Chan-o-cha also remained cautious. He neither rejected nor formally endorsed the proposal.
Concerns over national unity remained the strongest argument against the project. According to Storey, some in Thailand feared that the canal would physically divide the country into two parts.
They also believed it could strengthen separatist sentiment in the Malay-Muslim majority southern provinces of Pattani, Yala, and Narathiwat. The region has experienced armed conflict between the Thai military and insurgent groups since 2004.
Official government figures recorded 5,999 deaths from 10,116 security incidents since 2004. Meanwhile, several independent observers estimated that the death toll had exceeded 7,700 during the same period.
By the time the ISEAS study was published, the canal still lacked both the political will and the financial backing needed to become reality. More than three centuries after it was first proposed, Thailand's dream of building the Kra Canal remained unfulfilled.
References:
- Storey, I. (2019). Thailand's Perennial Kra Canal Project: Pros, Cons and Potential Game Changers. ISEAS Perspective, 2019 No. 76. ISEAS-Yusof Ishak Institute. https://www.iseas.edu.sg/wp-content/uploads/2019/10/ISEAS_Perspective_2019_76.pdf
- Sulong, R. S. (2012). The Kra Canal and Southeast Asian Relations. Journal of Current Southeast Asian Affairs, 31(4), 109-125. https://journals.sagepub.com/doi/full/10.1177/186810341203100405
- Lowy Institute. By Land or Sea: Thailand Perseveres with the Kra Canal. https://www.lowyinstitute.org/the-interpreter/land-or-sea-thailand-perseveres-kra-canal
- The Diplomat. (2025). Thailand's Southern Insurgency: A Conflict Fated to Last? https://thediplomat.com/2025/09/thailands-southern-insurgency-a-conflict-fated-to-last/
- Nation Thailand. Deep South Insurgency Marks 22 Years: 10,116 Attacks, 5,999 Deaths. https://www.nationthailand.com/blogs/news/policy/40060749
