A 1948 U.S. military document has surfaced confirming that the United States recognized the Liancourt Rocks, known as Dokdo in Korea, as part of Korean territory following World War II. The declassified record, dated 1948, explicitly states that it was established in September 1947 that the islands are part of Korea, providing historical evidence used by South Korea to support its sovereignty claims over the disputed islets.
The document emerged as part of a broader effort to analyze post-war administrative records from the U.S. military government. According to the report, the U.S. military identified the rocks as Korean territory during the period when the United States was overseeing the administration of the Korean Peninsula. This finding aligns with the terms of the 1945 Potsdam Declaration and the subsequent surrender of Japan, which required Japan to relinquish territories seized through aggression.
The Liancourt Rocks are a pair of small islets located in the East Sea, roughly equidistant from the coastlines of South Korea and Japan. While South Korea maintains an effective presence on the islands with a small detachment of guards and a lighthouse, Japan continues to claim the territory, leading to a long-standing diplomatic stalemate between the two East Asian neighbors.
Why the 1948 U.S. Military Document Matters for Sovereignty
The discovery of this document is significant because it provides a contemporary administrative record from a third-party superpower that held operational control over the region. By stating that the islands were “clearly established” as part of Korea by September 1947, the document suggests that the U.S. military did not view the islets as Japanese territory during the critical transition of power after 1945.
South Korean officials have historically pointed to the 1945 Instrument of Surrender and the subsequent Allied directives as the legal basis for the return of Dokdo. Specifically, Supreme Commander for the Allied Powers (SCAP) directive No. 275, issued in January 1946, excluded the Liancourt Rocks from Japanese administrative authority, listing them alongside Jeju Island and Ulleungdo as territories Japan must vacate.
The 1948 record reinforces this timeline, indicating that the U.S. military’s internal consensus remained consistent with the SCAP directives. For South Korea, these documents serve as “smoking gun” evidence that the international community, led by the U.S., recognized the islands as Korean before the formal establishment of the Republic of Korea government in August 1948.
How Japan and South Korea Contrast Their Claims
The dispute over the islands involves two fundamentally different interpretations of 20th-century history. South Korea bases its claim on historical records dating back to the Silla Dynasty in 512 AD and the aforementioned post-WWII U.S. documents. Seoul argues that Japan’s 1905 incorporation of the islands was an illegal act of colonial aggression that was nullified by the end of World War II.
Japan, conversely, maintains that it legally incorporated the islands in 1905 and that the 1951 Treaty of San Francisco—which officially ended the war between Japan and the Allied powers—did not explicitly list the Liancourt Rocks as territory Japan had to renounce. Tokyo argues that the omission of the islands from the list of territories to be returned to Korea implies they remained Japanese.
However, the 1948 military document complicates Japan’s narrative by showing that the U.S. military, which drafted the Treaty of San Francisco, had already internally acknowledged the islands as Korean years before the treaty was signed. This suggests a gap between the U.S. military’s operational recognition and the final legal wording of the peace treaty.
The Geopolitical Impact of the Liancourt Rocks Dispute
The tension over the islets extends beyond a mere territorial disagreement; it is tied to national identity, maritime resources, and strategic positioning in the East Sea. The waters surrounding the rocks are rich in fishing grounds and are believed to hold significant deposits of methane hydrates, a potential future energy source.
The dispute also affects the trilateral security relationship between the U.S., Japan, and South Korea. While the U.S. officially maintains a neutral stance on the sovereignty of the islands, urging both parties to resolve the issue through diplomatic channels, the release of historical U.S. documents often creates friction. Japan frequently views the highlighting of such records as a challenge to its legal claims, while South Korea views them as a validation of historical truth.
Current South Korean policy involves “effective control,” meaning the government does not seek negotiations over the islands because it considers the sovereignty issue already settled. Japan, however, continues to propose taking the dispute to the International Court of Justice (ICJ), a move South Korea has consistently rejected.
What Happens Next in the Territorial Dispute
The introduction of the 1948 document is expected to be integrated into South Korea’s official historical archives and used in diplomatic briefings to strengthen its position. It is likely that the South Korean Ministry of Foreign Affairs will use this evidence to counter Japanese claims in international forums.
There is no scheduled international hearing or court date for the dispute, as South Korea refuses to acknowledge the need for legal arbitration. The next significant checkpoints will likely be the annual reports on territorial disputes and the continued diplomatic exchanges between Seoul and Tokyo regarding regional security cooperation.
Readers interested in the legal history of the region can find further documentation on the Ministry of Foreign Affairs of the Republic of Korea website, which provides the government’s detailed legal and historical justifications for its sovereignty over Dokdo.
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