The San Juan Island Crisis, known colloquially as the "Pig War" between the United States and the British Empire in the summer of 1859, was a sovereignty dispute that brought the two states to the brink of military conflict. While the crisis was triggered by an American citizen killing a British-owned company's pig, the underlying cause was a long-standing territorial dispute stemming from the geographical ambiguities in the 1846 Oregon Treaty. This crisis, which concluded without any military casualties, is significant because it demonstrates how a local property dispute can escalate into international tension and ultimately be resolved through diplomatic intervention and international arbitration.

The Roots of the Crisis: The Oregon Treaty and Border Uncertainty

The legal basis for the dispute lies in the Oregon Treaty, signed between the United States and Britain in 1846. The treaty established the North American border at the 49th parallel, but stipulated that, where this line reached the Pacific, it would pass "through the middle of the channel separating the continent from Vancouver Island," with the intention of preserving the integrity of Vancouver Island and leaving it with Britain. This phrase in the treaty text left room for interpretation regarding the geography of the region. There were two primary waterways between the continent and Vancouver Island:

• Haro Strait: Wider waterway passing west of the island.
• Rosario Strait: A narrower waterway running east of the island.

 

The sovereignty of the San Juan Islands, located between these two straits, depended on which channel the border passed through. The United States claimed the islands, arguing that the more geographically distinct Strait of Haro should be the boundary. Britain, on the other hand, claimed the islands as its own, citing the Strait of Rosario as its historical navigation route. It is believed that the treaty negotiators intentionally left this geographical detail vague to resolve the larger mainland border. This diplomatic uncertainty created a sovereignty vacuum in the region in the years that followed.

Actual Situation on the Island: Competing Settlements

The legal vacuum created by the treaty caused San Juan Island to become an area de facto inhabited by both the United States and Britain.

• British Presence: The Hudson's Bay Company (HBC), Britain's commercial and administrative power in the region, established an economic presence on the island by establishing a large sheep-raising facility called "Belle Vue Farm." This facility served as a concrete demonstration of Britain's claim to sovereignty over the island.
• American Presence: Under the Donation Land Claim Act of 1850, numerous American settlers came to the island and claimed land for agricultural purposes. Their presence also bolstered the US's claim of sovereignty.

 

This situation has created a tense environment on San Juan Island where civil elements and economic interests of two rival nations exist side by side and where legal jurisdictions intersect.

^{Representative Image of the Pig War Incident on the Border of America and Great Britain (Designed with Artificial Intelligence)}

Triggering and Escalating the Crisis

On June 15, 1859, American farmer Lyman Cutlar escalated existing tensions when he shot and killed a pig belonging to Hudson's Bay Company employee Charles Griffin that had strayed onto his land. The incident quickly escalated from a simple property dispute into a sovereignty crisis:

• Compensation Dispute: Griffin's demand for $100 in return for Cutlar's offer of $10 in compensation showed that the parties were not willing to compromise.
• Jurisdiction Crisis: When Hudson's Bay Company officials threatened to arrest Cutlar under British law, American settlers sought protection from the US military. This request raised the question of whether a US citizen could be subject to British jurisdiction, thus internationalizing the crisis.

Military Buildup and Diplomatic Intervention

An American force under Captain George Pickett landed on the island under the orders of General William S. Harney, Commander of the US Army's Oregon Department. In response, British Royal Navy warships were dispatched to the area. By August 1859, five British warships carrying over 2,000 personnel and over 70 cannons faced off against 461 American soldiers and 14 cannons.

 

A military conflict was averted thanks to the intervention of senior commanders. Admiral R. Lambert Baynes, Commander of the British Pacific Fleet, refused Vancouver Governor James Douglas's order to intervene with American forces, arguing that "he would not start a war between two great nations over a pig." On the US side, President James Buchanan dispatched Chief of the Joint Chiefs of Staff General Winfield Scott to the region to defuse the crisis. At General Scott's suggestion, it was agreed that the island would be jointly occupied by both countries, with a maximum of 100 troops each, until a final solution could be found.

^{Representative Image of Diplomatic Talks Between the US and the UK (Generated with Artificial Intelligence)}

International Arbitration Process

After approximately 12 years of joint occupation, the two sides agreed to submit the status of the San Juan Islands to international arbitration under the 1871 Treaty of Washington. Kaiser Wilhelm I, Emperor of Germany, was appointed as the arbitrator.

 

A three-person, impartial arbitration panel appointed by the Kaiser reviewed the parties' arguments. The United States defended the Strait of Haro, the geographically most distinct boundary as defined by the treaty text, while Britain argued that the Strait of Rosario should be the decisive factor for historical use and safety of navigation.

 

On October 21, 1872, Kaiser Wilhelm I, following the commission's recommendation, announced his final decision. According to the decision, the border would run through the Strait of Haro, and the entire San Juan Islands would be ceded to the United States. Following the decision, British troops withdrew from the island, and the crisis ended peacefully.

Historical Significance

Although the Pig War ended without loss of life, it had important consequences for the history of international relations and diplomacy:

• International Arbitration: The crisis demonstrated that two major powers could resolve a dispute by accepting a binding decision from a third party rather than resorting to military conflict, and served as an example of the effectiveness of international arbitration.
• Anglo-American Relations: This event is considered one of the steps symbolizing the transition to a period in which cooperation and the search for diplomatic solutions came to the fore in relations after the ongoing rivalry between the two countries in the 19th century.
• Crisis Management: This demonstrated the potential for a local incident to rapidly escalate into an international crisis under the current political and legal uncertainty. Furthermore, the intervention of senior command levels to control the crisis despite the potential for military escalation is a prime example of crisis management.

 

Ultimately, the Pig War remains a historical case that examines the functioning of international law, diplomacy and peaceful resolution mechanisms.