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The Treaty of Washington and Neutrals’ Duty of Due Diligence

By: Inge Van Hulle (Tilburg University)

On 14 September 1872, the arbitral tribunal that convened in the city hall of Geneva to consider a number of outstanding claims between the United States and Britain following the American Civil War awarded an indemnity worth US$15.5 million of gold to the United States for the damage caused by Confederate cruisers to Union shipping that had received support through Britain’s unneutral services. This arbitral decision became known as the Alabama arbitration and acquired fame within the history of international law for a number of different reasons: the staggering amount of the indemnity; the precedent which the resort to arbitration provided for later initiatives to promote peaceful dispute settlement; and, finally, the role that its founding document, the Treaty of Washington (143 CTS 145), played in sharpening the duties of neutrals.

During the nineteenth century, the content of the laws of neutrality were in a state of flux. While the Paris Declaration of 1856 (115 CTS 1) had laid down a number of rudimentary rules concerning the prohibition of privateering, the requirement of mounting effective blockades and the commercial rights of neutrals, states’ interpretation of neutrality as pro-belligerent versus pro-neutral depended to a large extent on the strength of their respective navies. Importantly, in the Treaty of Washington British conceptions of neutrality were abandoned to the advantage of American interpretations, which favoured a duty of due diligence on the part of neutrals. Britain traditionally supported the idea that the policing of neutral duties was the responsibility of belligerents, who were required to enforce neutrality through the mounting of effective blockades and prize courts that could adjudicate captured vessels. The Treaty of Washington, however, sharpened the obligation of due diligence for neutral countries and shifted the burden of responsibility for the maintenance of impartiality and abstention to neutrals.

The conflict between Great Britain and the United States that led to the signature of the Treaty of Washington started when on 13 May 1861 the British government declared itself neutral in the civil war raging between the Union and the Confederacy. The Confederacy—which was not a signatory of the Paris Declaration—immediately issued letters of marque to merchants willing to target Union shipping as privateers. However, as the Confederacy lacked a navy and needed to break the Confederate blockade of its ports to safeguard its economic viability, it actively sought to acquire arms and shipping in neutral countries, including in Britain.

Britain’s responsibilities as a neutral were enshrined in domestic law through the adoption in 1819 of the Foreign Enlistment Act. The Act was originally adopted to stem the flood of British volunteers who joined Spanish-American insurgent armies during the 1810s, and it thereafter criminalized the enlistment by British subjects in the forces of foreign belligerents when Britain had pledged neutrality. The Act also contained provisions that prohibited the sale of arms and equipment and the sale and outfitting for war of ships in British ports. However, the Act contained an important loophole: it applied only to fully equipped vessels and not to half-finished ships. As a result, vessels secretly commissioned by the Confederacy that were built in British ports had the character of neutral merchantmen when they set sail and were equipped on the open seas or in another port, where they hoisted the Confederate flag as war ships outside of British jurisdiction. The damage done to Union ships inflicted by thirteen of such Confederate vessels, including the Alabama, would eventually be adjudicated through arbitration.

The American government accused Britain of failing to respect the due diligence required of neutrals by displaying hostility towards the Union and by thus neglecting its duty of impartiality. As complaints from the Union government reached Britain, the British governmental advisors and courts remained ambiguous about Britain’s inability to prevent the covert preparation of Confederate ships within its ports under the Foreign Enlistment Act. However, a commission of inquiry established in 1867 ruled that the provisions of the Act required more stringency in order to bring British law in line with international legal responsibilities. In the nick of time, the updated Foreign Enlistment Act was adopted by Parliament in 1870 at the start of the Franco-Prussian war.

As tensions between Britain and the United States rose in the aftermath of the American Civil War, negotiations were underway to settle the Alabama claims and other outstanding disputes by joint commission. Britain favoured a general, unrestricted arbitration, yet the US government insisted on drafting guiding principles for the assessment of the claims by the arbitrators. The resulting ‘Three Rules of Washington’, ratified in 1871 and proposed by the US, were grafted retrospectively on the premise that Britain had neglected its neutral duties. The rules established due diligence as a guiding principle. Firstly, due diligence was required of neutrals in preventing the fitting out, arming, or equipping of any vessel where there was ‘reasonable ground’ to believe that it was intended to cruise against a belligerent power. This included preventing its departure. Secondly, neutrals could not permit or suffer its ports or waters to be used for naval operations against belligerents, for the renewal of supplies, or for the recruitment of personnel. Finally, due diligence of neutrals was required to prevent the general violation of all the above duties, including from all persons within its jurisdiction. The Treaty of Washington further precluded Britain’s ability to rely on the inadequacy of its domestic law, ie the Foreign Enlistment Act. Britain voiced its disagreement with the rules by adding to the provisions that it did not consider the rules of Washington as a statement of the principles of international law in force at the time that the claims came into existence.

The arbitral commission consisted of five members, which included representatives from Italy, Switzerland, and Brazil in addition to those from Britain and the United States. The commission unanimously found against Britain on the subject of the Alabama, and found against Britain on the vessel Florida on a basis of four to one. It described that the assessment of the duty of due diligence hinged on its exercise by neutrals ‘in exact proportion to the risks to which either of the belligerents may be exposed, from a failure to fulfil the obligations of neutrality on their part’. In 1907 the reference to due diligence was removed during the Second Hague Peace Conference. This, however, did not resolve the indeterminacy of the exact content of neutral duties or unneutral service. As a result, the extent to which neutrals needed to police their own subjects and territory remained the crux of many future discussions.

Alabama Claims of the United States of America against Great Britain, Arbitral Award of 14 September 1872, (2011) 29 RIAA 125–34; 145 CTS 99.

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