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On a hot and uneasy day — July 18, 1936 -civil war erupted in Spain.

What began as a military coup d’etat by Spanish military officers against the government of Spain turned into one of the most ferocious and bitter civil wars of this modern age. It was a war between the landed and landless; church against laity; democracy against facism.

Classically, Europe took sides: the Germans and the Italians supported the Spanish military rebels and the Soviets backed the Spanish government. France and Britain’s leaders, Blum and Chamberlain, both with timid and uncertain and uncertain leadership, fueled the flames of strife with ambivalence.

German and Italian intervention in the Spanish Civil War was almost immediate: about 8,000 German aviation personnel and technicians, and eventually over 60,000 Italian troops swung in behind the Spanish rebels under Franco. These two countries shipped vast amounts of muni tiona, supplies and hospital goods, and also provided occasional direct intervention in the form of German and Italian planes and ships on behalf of the Spaniards.

For the other side, the Spanish Government, the Soviets furnished supplies with approximately thirty to forty Russian ships traveling to Spain each month for a period of 18 months. None of the ships carried war material exclusively, because legitimate cargo was necessary to disguise the arms and because Spain needed other supplies in addition to war materials. Half or more of each shipload was food, clothing, medicines, fuel oil or transport trucks. The remainder consisted of ammunition, arms, tanks and planes. Of major importance was the Soviet inspired International Brigade formed of
volunteers and army unit leaders from countries around the world. The Soviet Union formally took
no other direct part in the war.

By International Law, the government of Spain held the right to buy arms and military supplies from the world market. On the other hand, the rebels being against a legally-constituted government had no such right. Despite this situation, twenty-five nations subscribed to a policy of non-intervention in this civil war. However, neither the Germans nor the Italians paid any attention to the law or the nonintervention policy. Both nations openly delivered materials to the rebels. In August 1936, the Non-Intervention Committee (NIC) was formed as an instrument to permit intervention in the name of non-intervention, thus avoiding a confrontation for which no country was ready. For
some months, the NIC discussed a neutral land/sea patrol. They initiated an international blockade
of Spain in April 1937 whereby the German and Italian navies would patrol (as “neutrals”) the
Republican coast. British observers were also stationed on the French and Portuguese land frontiers.

Unidentified Submarines

Beginning in late 1936, and continuing through most of 1937, “unidentified submarines” torpedoed
neutral merchantmen in the coastal waters of Spain, in the Western Mediterranean and as far
east as the Aegean Sea. In the course of April and May alone, approximately thirty-five neutral
ships of British, Greek, Danish and other nationalities were torpedoed and sunk.

In December 1936, the Soviet merchantman “Komosomol11 was sunk in the Mediterranean by a torpedo. Later that year, two more Soviet ships were torpedoed and sunk: the merchantman “Tuniyaev” at Algiers on its way to Port Said on August 30th; and the Russia steamer “Blagaev,” sunk off Skyros on September 1st. The Soviet Union reacted quickly to the loss of its shipping. A formal protest was sent to the Great Powers of Europe accusing the Italians of using their submarines  against neutral shipping.

At that time, it was difficult to place blame because the sinkings were made by submarines or by unmarked airplanes, but it is now known that the attacks were carried out by the Nationalists and Italians to cut down shipments to Republican Spain and to stop Russia from sending aid.

The submarine attacks had the desired effects. Foreign trade was reduced considerably, and the
Soviets became more and more fearful of losing their none too plentiful merchant marines and of
becoming too deeply involved in a crisis over the sinkings of their ships.

The British Government, despite the losses in shipping, was unwilling to initiate positive actions to stop the destruction or its own merchantmen, let alone those or its allies. It is important to remember that the British Empire at this time possessed a most formidable navy.

The only time the British Government was stirred to take action to stop the brazen attacks by Italian submarines and bombers against British and other ships in the Mediterra~ean came in September 1937. British Charge d’Affaires, Anthony Eden, forced the reluctant Chamberlain government to take a determined position in this matter. The British Cabinet decided it was necessary to reinforce their naval forces in the Mediterranean. At the same time, French Foreign Minister, Yvon Delbos suggested all the Powers bordering on the Mediterranean hold a conference in Nyon, Switzerland to take joint action to ensure the safety of ships from such attacks. When the invitations went out on September 6th, twelve countries had been invited to attend. The countries invited were the six Mediterranean
countries of France, Italy, Yugoslavia, Albania, Greece, and Egypt, along with Great Britian, Germany, Rumania, Bulgaria, Russia and Turkey.

Nyon Arrangement

From that conference which began on September 9, 1937 came the Nyon Arrangement, an “international agreement for collective measures against piratical attacks in the Mediterranean by
submarines.”4 This was one of many agreements since World War I directed at the control of submarines in times of peace and war. The main features or the plan were designed to solve the
problem of “piracy” by destroying any submarine found attacking shipping, or even suspected of
such an attack if found in the vicinity of a torpedoed ship. Under the arrangement, Great Britain and France were to cooperate in patrolling the sea lanes from the Dardanelles and Suez to Gibraltar and from North Africa to France. Second, the participating Mediterranean countries, with the exception of France, would patrol their own territorial waters and would aid each other, England and France if called upon. Third, it was agreed that Russia would not participate in the Mediterranean patrol. (This
aspect of the arrangement was welcomed by Russia at the time because the Soviets had just embarked on their naval rearmament plan and were in no position to provide any great number of ships for the patrol.) Fourth, it was agreed Italy was to be invited to join in the patrol of the
Mediterranean. Fifth, if piracy ever spread into the Black Sea, then the Powers bordering that sea
would carry the responsibility of cooperating among themselves to stop it. In addition to these
features, the plan also called for a surface ship to accompany each submarine entering Mediterranean

By September 17, the Nyon Arrangement had been accepted and Italy was considering adoption of the plan. Following brief negotiations between the Charge d’Affaires from England and France with
Italy’s Foreign Minister Ciano, Italy agreed to accept the Nyon proposal, and consequently, the
Italians sought to share in these Anglo-French anti-submarine patrols in their “mare nostrum.”
“Pirate” submarine attacks ended.

Other than being an interesting historical incident, why is the Nyon Arrangement important to
naval leaders, particularly to those responsible for submarine operations? One reason is that this
treaty marked the beginning of naval cooperation and communications between countries such as
France and Great Britain. Another significant fact is that Nyon is one of a train of agreements
and protocols which over the past 115 years has been directed specifically at the control of
submarines in the performance of their assigned tasks.

Such international restrictions will continue to develop over the years ahead, especially as the control of the seabeds moves toward reality, and as at-sea tactical and strategic nuclear weapons
become inceasingly important and prevalent. Indeed, as nuclear cruise missiles go to sea and
their targets are over the horizon or land-based, it would appear that the attention of nations
will begin to concentrate on past and newly legislated international law, agreements and
protocols to inhibit weapon use from submarine platforms.

In summary, the Nyon Arrangement was a minor agreement alongside other treaties of that time.
But, it is significant that the Nyon Arrangement forms one link in a chain of agreements binding
the use of submarines. With that in mind, submarine leaders must carefully assess in times of peace their planning and tactical schema in the grand strategy of crisis and war, lest the submarine sword remain sheathed when most needed.

Dr. Jon L. Boyes, Vice Admiral, USN {Ret)




Some brief comments on particular aspects of ocean law raised in the article might be of interest to the reader.

The word “piracy” in popular usage covers a great variety of activities . Its use in the period of the Spanish Civil War, moreover , reflected that tendency. But in fact and in law, piracy is restricted to illegal acts of violence committed for private ends of the crew or passengers of a private ship against another ship on the high seas. In the Spanish Civil War, the submarines in question were unquestionably not privately owned or privately operated nor did they conduct their attacks for private ends such as the obtaining of wealth, etc. Thus, the torpedoing of ships during the Spanish Civil War were not acts of piracy but acts of war committed by the submarines of a belligerent against the merchant ships of other states.

To sink a ship, with torpedoes or otherwise, is an act of war. If such a ship is not flying the flag of a belligerent, it still has however a right to react in self-defense. The right of self-defense was obvious when British, Greek, Danish or Soviet merchantmen were sunk. In exercising that right, non-belligerents may respond on the high seas where the act or threat to the security of the flag state takes place . It follows then that any of the above mentioned states could have responded to the torpedoing of their ships by using force against the offending submarines, while maintaining their neutral status, since they would have met the two tests of (1) whether the act was a threat to their security and (2) whether the measures to be taken to repel the threat were reasonable and not beyond the limits of the threat being dealt with.

In regard to the conduct of submarine warfare, submarines are entitled to take full advantage of their ability to strike warships without warning using stealthy, submerged approaches. The sinking of commerical ships, however, raises some difficult questions.

Although maritime warfare directed against commerce is legal, certain means of pursuing it are illegal. In particular, Germany’s practice in both world wars of setting up large operational zones and then making submarine attacks without warning on all vessels neutral or otherwise found in those zones was widely condemned. In the Nuremberg war crimes trials, Admirals Erich Raeder and Karl Doenitz were convicted of violating International Law in this respect. On the other hand, the unrestricted
submarine warfare against an enemy’s merchant marine, practiced by the Axis and Allies alike in
World War II, as a violation of International Law, is still an unsettled point. This practice was complicated by the fact that merchant vessels were armed, convoyed, and ordered to fire upon or
ram submarines on sight. Furthermore, almost all nations integrated merchant vessels into the
warning net of naval intelligence. These acts seemingly caused merchant vessels to be treated
as warships and made them liable to attack without warning.

The new Law of the Sea Treaty of 1982 might also hold some implications for the operation of submarines under the high seas. Although the US is not a signer of this Treaty, 118 nations are.
The force of this consensus could then possibly affect submarine operations particularly in the
established exclusive economic zone (EEZ) 200 miles off the shores of coastal countries. In this zone, coastal states, while recognizing freedom of navigation might attempt to control the movement of foreign submarines as a pollution control measure to prevent damage to their economic resources within the zone. Similarly, coastal states might worry about damage to fish nets — threatening their fishing industry, (an economic resource). Although, no speciric example of coastal state control of submarine movement in the EEZ has been evidenced to date, the po~sibilities generated by the Law of the Sea Treaty should be contemplated and appropriate counter actions readied.


Founders: Capt. L.H. Neeb, USN (Ret)

LCDR Dural Browning, USN (Ret)
Capt. George Martin, USN (Ret)
VAdm. F.J. Harlfinger, USN (Ret)
RAdm. F.B. Warder, USN (Ret)

Advisors: LCDR David R. Banner, USNR (R)
Cdr. David A. Brown, USNR (R)
Associates: LCDR P.J. Keuhlen, USN

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