In the first months of World War I, merchant vessels from countries across Europe continued to visit ports in the United States, and, by September 1914, it became necessary for the US Department of State to clarify their status. It was difficult to ascertain when a merchant vessel, armed for protection, became a warship, and it was very important to determine the boundaries, as the treatment of a ship while in a United States port was vastly different depending on whether it was a merchant vessel or a vessel of war. The United States was determined to remain neutral “in thought as well as action,” according to President Woodrow Wilson, and if foreign warships were improved, outfitted, or supplied with goods or ammunition, it could be seen by other belligerents as proof that the United States was no longer neutral. If a merchant ship was simply protecting itself while engaging in lawful trade, however, it would be welcomed in US ports and protected from attack while there. This report determined the criteria for determining when an armed merchant vessel crossed the line and would be considered a vessel of war.

In the first months of World War I, merchant vessels from countries across Europe continued to visit ports in the United States, and, by September 1914, it became necessary for the US Department of State to clarify their status. It was difficult to ascertain when a merchant vessel, armed for protection, became a warship, and it was very important to determine the boundaries, as the treatment of a ship while in a United States port was vastly different depending on whether it was a merchant vessel or a vessel of war. The United States was determined to remain neutral “in thought as well as action,” according to President Woodrow Wilson, and if foreign warships were improved, outfitted, or supplied with goods or ammunition, it could be seen by other belligerents as proof that the United States was no longer neutral. If a merchant ship was simply protecting itself while engaging in lawful trade, however, it would be welcomed in US ports and protected from attack while there. This report determined the criteria for determining when an armed merchant vessel crossed the line and would be considered a vessel of war.

On August 4, 1914, Britain declared war on Germany after the German Army pushed into neutral Belgium on its way to France. Britain’s Navy, which was vastly superior to its ground forces, began an immediate blockade of German ports and declared the entire North Sea to be a war zone. This meant that US ships still trading with Germany were liable to be seized and searched. Though the United States protested vigorously, the blockade was effective, and US trade with Germany was severely curtailed.

The US economy relied on trade, however, and the United States was eager to be able to continue welcoming merchant vessels into its ports. German trade slowed to a trickle, but the Allies (Britain, France, and Russia) relied heavily on favorable treatment at US ports. In the course of the war, Allied trade with the United States rose from $825 million in 1914 to $3.2 billion in 1916. At the same time, the United States was aware that if it was thought to be supplying the war effort of Germany’s enemies, it would lose its neutral status, and American merchant vessels would be subject to attack.

To make matters more complicated, Britain and Germany both equipped merchant vessels with weapons. Though it was widely accepted that merchant vessels should be able to defend themselves if attacked, some of these vessels were employed as raiders, attacking other merchant ships and capturing or sinking them. Germany employed a fleet of famous raiders, some with guns and on-board aircraft that were cleverly disguised. The US State Department crafted its guidelines to make it clear that merchant ships that could prove they were armed for defensive purposes only would be allowed into US ports; they also established a mechanism for proving that these vessels would remain neutral. The guidelines also made it clear that the United States would engage in trade with any merchant vessel that met these criteria.

The distinction between civilian and military vessels was crucial during World War I, and it was a German submarine’s sinking of the British passenger liner Lusitania in 1915 that moved popular opinion in the United States away from neutrality. When this statement was written in 1914, however, the United States was committed to neutrality and sought to be transparent in its dealings with the warring nations of Europe. Its determination about which vessels met the criteria for trade changed as the war progressed, but in the opening days of the war, it was important to regulate the role of US ports to avoid not only the appearance of involvement on one side of the conflict or another, but to ensure that naval conflict did not take place in US ports.

This statement was issued by the US Department of State, commonly referred to as the State Department. First created in 1789, the State Department was briefly known as the Department of Foreign Affairs. The State Department is the executive agency responsible for the international relations of the United States, much like other nations’ foreign ministries, and is headed by the secretary of state, the president’s principal foreign policy advisor. When this statement was written, the secretary of state was William Jennings Bryan, former three-time presidential candidate (1896, 1900, 1908) who served in the Wilson administration from March 5, 1913, until his resignation on June 9, 1915.

This statement was necessary to define the status of armed merchant vessels and determine how they should therefore be treated. The statement says that if these vessels are identified as commercial, and not military, they would be granted certain privileges in a friendly port, including protection from military vessels. There is also a provision to detain military vessels for twenty-four hours after the departure of a merchant vessel from an opposing nation, to protect it from attack when it left port.

On the other hand, the statement specifies that military vessels are to be treated quite differently. The statement says that time allowed in port is restricted, supplies that can be loaded and unloaded are to be tightly controlled, and the number of military vessels permitted to be in port at a single time is limited. In addition, if the United States is seen as contributing to the modification of a merchant vessel into a military one, it would antagonize the other belligerents, and merchant vessels have to meet and maintain standards that allow them to access US ports.

The statement first acknowledges that it is often necessary for merchant ships to carry ammunition and other military supplies during times of war. It also acknowledges that if a vessel carries such things, it can be assumed to be a vessel of war; indeed, during World War I, many passenger and cargo vessels were adapted and modified to serve as vessels of war. Therefore, it is the responsibility of the ship’s officers to prove to the United States that the “vessel carries armament solely for defense” and is still legitimately involved in trade.

The statement’s criteria for determining the difference between a commercial vessel armed for defense, and a military vessel armed for attack, are very specific. The number and placement of guns is important. The caliber of the guns aboard should not be more than six inches. Other guns and small arms aboard the ship “are few in number,” and there are to be no guns mounted on the front of the boat that could be used offensively. Ammunition and fuel are to be carried only in small quantities.

The history of the ship, its passengers, and the trade that it claims to be engaged in are also important. The crew of the ship should be “the same as those on board before war was declared”; the ship should stick to trade routes established before the war, and require a similar amount of fuel. Passengers on board are also to be carefully examined and may not be military personnel, or anyone who would be considered fit for military service. Ships should expect to be thoroughly examined before they are allowed in port, and a report would be made about them to the government, which would determine whether they had met the criteria to be released from the assumption that they are war vessels.

Despite these specific instructions, the end of the statement acknowledges that there are some vessels, which, despite meeting the specific criteria for merchant vessels, may demonstrate the “intention” to be used in war. It is very important, therefore, to have the burden of proof lie with the ship.

The primary theme of this statement is the desire of the United States to remain neutral at the outbreak of World War I, and the difficulties involved in doing so. Commercial vessels needed to be armed for their own protection, but were often interchangeable with vessels used offensively. The way the United States treated foreign ships while in US ports was determined by their status. This document clarifies what criteria a vessel needed to meet in order to be treated as a merchant vessel.

• American Society of International Law. “The Status of Armed Merchant Vessels.”American Journal of International Law 9.1 (1915): 188–89. Print.
• Carlisle, Rodney.Sovereignty at Sea: U.S. Merchant Ships and American Entry into World War I. Gainesville: UP of Florida, 2011. Print.
• Tuchman, Barbara.The Guns of August. New York: Ballantine, 1962. Print.
• Tucker, Robert W.Woodrow Wilson and the Great War: Reconsidering America’s Neutrality, 1914–1917. Charlottesville: U of Virginia P. 2007. Print.