The Anglo-French pledge against a separate peace

On 28 March 1940 the Anglo-French Supreme War Council met in London – the joint body in which the prime ministers, ministers and commanders of the two powers concerted the conduct of the war. It was its sixth meeting since the first one at Abbeville in September 1939, and the first attended by Paul Reynaud, who a week earlier had become head of the French government. The most widely publicised outcome of the meeting was a joint declaration by the two governments: during this war neither Britain nor France would negotiate or conclude an armistice or peace treaty except by mutual agreement. That same day the Council took decisions that were at last to bring the Allies out of the inactivity of the Phoney War: it resolved to mine the Norwegian coastal waters through which Swedish iron ore was shipped to Germany, and to float mines down the Rhine. It also agreed that the possibility of striking at the Soviet oilfields in the Caucasus should be studied further.

On 28 March Britain and France thus entered into a formal agreement that neither would seek a separate peace with Germany. It was not, however, a treaty in the strict sense, but a solemn declaration by the two governments, announced in the communiqué issued after the meeting and not submitted to the parliaments for ratification. This form turned out to matter three months later.

After the fall of Finland

The Council met at a bad moment for the Allies. On 12 March Finland had signed a peace in Moscow that ended the Winter War before the Allies had managed to send the promised expedition. The plan adopted by the Council on 5 February, which was to bring British and French troops to Finland through Narvik and the Swedish iron-ore mines, had lost its purpose, and the units assembled for it were dispersed. After Poland, a second country to which the West had promised help had gone under. In France the Finnish defeat brought down the government of Édouard Daladier. Reynaud took power as the advocate of a war waged harder and faster, but with very weak backing in the Chamber of Deputies and with Daladier as Minister of National Defence and War in his own cabinet.

On 25 March the new Prime Minister sent London a note setting out a programme of action. He wrote that the existing system of consultation did not produce quick decisions and that the Allies were treating neutrality too legalistically: in the name of the common and lasting interests of free nations they must be ready to set formalities aside and act, if need be, by imposing their will. He reduced the conduct of the war to two questions. The first was physical: how to cut Germany off from its supplies, especially of iron and oil. The second was psychological: how to seize the initiative so clearly that the neutrals would once again believe in an Allied victory. Reynaud proposed taking immediate control of shipping in Norwegian territorial waters and occupying the points on land needed to maintain it, cutting Germany off from Caucasian oil even at the cost of a break with the Soviet Union, and examining the possibility of sending submarines into the Black Sea.

The British cabinet, which discussed the note on 27 March, regarded most of these ideas as unrealistic. It had no intention of occupying points on Norwegian soil, and the proposals on oil ignored the neutrality of Turkey, without whose consent no warship could pass through the Straits into the Black Sea. What the cabinet did care about was Operation Royal Marine – floating mines down the Rhine and other rivers flowing into Germany to destroy barges and bridges. The French had already rejected this idea once, fearing German reprisals against their factories; it had been pressed since the autumn of 1939 by the First Lord of the Admiralty, Winston Churchill. London decided to use its consent to the mining of Norwegian waters as a lever to win Paris over to it.

The meeting in London

The British side was represented by Prime Minister Neville Chamberlain, the Foreign Secretary Lord Halifax, Churchill, the Secretary of State for War Oliver Stanley and the Secretary of State for Air Kingsley Wood. Reynaud, who was also Foreign Minister, came with the Minister of Marine César Campinchi, the Air Minister Victor Laurent-Eynac, the ambassador in London Charles Corbin and the Secretary-General of the Quai d’Orsay, Alexis Léger. They were accompanied by the Commander-in-Chief, General Maurice Gamelin, the commander of the fleet, Admiral François Darlan, and the head of the air force, General Joseph Vuillemin. Daladier was not in the delegation.

Chamberlain opened the meeting with a review of the situation after the fall of Finland. He said that the Allies must take action that would harm Germany, impress the neutrals and sustain the spirit of their own peoples, preferably action that came as a surprise. He recalled how strongly British public opinion had been affected – far more strongly than their real importance warranted – by the German raid on Scapa Flow on 16 March and the British reprisal on the island of Sylt. He recommended Operation Royal Marine as a surprise blow that would also put additional strain on the German railways, and gave assurances that it would not bring reprisal raids down on France, because the Germans would rather strike at Britain. At the same time he warned against believing in short cuts. The Allies’ main weapon remained the blockade, whose effects came slowly, and the worst possible end to the war would be a “patched-up” peace with Hitler.

Reynaud agreed that the war must be fought to the finish. He spoke frankly about the mood in France: German propaganda was persuading the French that the Reich had no quarrel with them, that the war had broken out because of the British “blank cheque” to the Poles – the guarantee of March 1939 – and that France had been dragged into it against her interests. The Germans, in his view, were counting on the discouragement of the millions of Frenchmen under arms and on the emergence of a government that would conclude a compromise peace at Britain’s expense. The German army was growing faster than the Allied armies, and an offensive in the west would be a very long time coming. Something “new” therefore had to be done, to force Germany to draw on its reserves of oil and raw materials.

Norway, the Rhine and Belgium

Reynaud accepted the plan for laying a minefield in Norwegian territorial waters and wanted it carried out immediately, and later also to tackle shipping from Luleå on the Gulf of Bothnia, through which ore could be shipped once the ice melted. As for the river mines, he said that the French War Committee had rejected them earlier for fear of reprisals, but might accept them in combination with other undertakings. On this basis the Council agreed a timetable, subject to the approval of the French War Committee. On 1 or 2 April the governments of Norway and Sweden were to receive notes warning them that the Allies would no longer allow Germany to profit from their neutrality. On the evening of 4 April Operation Royal Marine was to begin with mines released from the riverbank, and on 15 April its second phase, the dropping of mines from aircraft. On 5 April British ships were to lay mines in Norwegian waters to force the German ore carriers out onto the high seas, where the Royal Navy could intercept them. The British named this undertaking Operation Wilfred.

In the afternoon the Council turned to Belgium and the Netherlands, which were clinging to their neutrality and refused to admit Allied troops before a German attack. It was agreed that if Germany attacked Belgium, the Allies would enter the country at once, without waiting for a formal invitation, in accordance with the Dyle Plan adopted in the autumn. If Germany attacked the Netherlands and the Belgians went to its aid, the Allies would immediately support Belgium. If, on the other hand, Belgium remained neutral, the Allies considered themselves entitled to enter its territory in order to help the Dutch, but did not commit themselves to any specific action.

Oil from Baku

Oil caused the most disagreement. Chamberlain pointed out that Germany obtained it from Romania, from Galicia and from Baku. Romania was in no position to stand up to Germany, and Turkey, which might support it, was too poorly armed. Britain proposed studying the possibility of an attack on Baku and seeking Turkish support for Romania. Reynaud wanted more. He believed that the entire Baku oil region could be destroyed from the air, pressed for a quick decision and proposed sending bombs at once to French Syria, from where the aircraft were to take off. Chamberlain refused to commit himself to an attack. He asked whether it was in the Allies’ interest to extend the war to the Soviet Union and drive it closer to Germany, with which it had been doing an ever-growing trade since the February economic agreement. He also pointed to signs that Moscow wished to improve relations with the West: the Soviet ambassador in London, Ivan Maisky, had just proposed trade talks. Reynaud replied that the Soviets could not be trusted and might merely be playing for time to strengthen the defences of the Caucasus. In the end it was agreed that the possibilities of action in the Caucasus would be studied and preparations made, and that the Allies would spin out the talks with Maisky until they had decided on their policy towards the Caucasus. The British and French were already preparing the operation later called Pike, and two days after the meeting a British reconnaissance aircraft flew secretly over Baku.

The declaration

The political culmination of the meeting was the declaration announced in the communiqué. Its text read:

The Government of the French Republic and His Majesty’s Government in the United Kingdom of Great Britain and Northern Ireland mutually undertake that during the present war they will neither negotiate nor conclude an armistice or treaty of peace except by mutual agreement.

They undertake not to discuss peace terms before reaching complete agreement on the conditions necessary to ensure to each of them an effective and lasting guarantee of their security.

Finally, they undertake to maintain, after the conclusion of peace, a community of action in all spheres for so long as may be necessary to safeguard their security and to effect the reconstruction, with the assistance of other nations, of an international order which will ensure the liberty of peoples, respect for law and the maintenance of peace in Europe.

The initiative came from the British, who proposed a short text modelled on the London Declaration of 5 September 1914, in which Britain, France and Russia had undertaken not to conclude a separate peace with the Central Powers. According to some French studies, Daladier had opposed such a commitment, at least until Britain defined its contribution to the war more clearly, especially in the air. Reynaud accepted it. As he explained in the Chamber of Deputies on 19 April, he substantially amended the British draft. To the ban on a separate peace he added a ban on a separate armistice, because an armistice would disarm one of the allies before the terms of peace had been settled, and he added two paragraphs: on agreeing the conditions of security before any peace talks, and on community of action after the war. He called the declaration “a little peace treaty between the two of us”. The French remembered that after the previous war the Anglo-American treaty of guarantee promised to them in 1919 had never come into force, and the added paragraphs were meant to ensure that this time France’s security would be settled before anyone began to talk of peace. For London the main point was the certainty that France would not leave the war should she succumb to discouragement or to German offers.

The declaration was also a response to the German game of splitting the coalition. Ever since Hitler’s peace offer in the autumn, Berlin had repeatedly suggested that it had no quarrel with France, and in March the American envoy Sumner Welles had been travelling across Europe, listening in its capitals to various visions of a compromise. The announcement that the two powers would leave the war only together was meant to show the neutrals and the Germans that there was no hope of a separate peace with France. The undertaking resembled a clause of the Anglo-Polish alliance of August 1939, which likewise forbade either party to conclude a separate armistice or peace without the agreement of the other.

The text was submitted neither to the French Council of Ministers before it was signed nor to parliament for ratification. Reynaud bound the state to it on his own authority as head of government, and discussed the declaration in the Chamber only after the event.

The first disappointment

On 29 March the British cabinet approved the Council’s decisions. On 1 April, however, London learned that the French War Committee had refused its consent to Operation Royal Marine and was proposing to postpone it for three months, until the aircraft and armaments factories were less exposed to reprisals. The main obstacle was Daladier, who was supported by President Albert Lebrun. The British were bitter, feeling that their ally was backing out of an agreed bargain. Churchill, who talked with Daladier in Paris on 5 April, concluded that further pressure was pointless. London decided to mine the Norwegian waters on its own: the notes were handed to the governments in Oslo and Stockholm on 5 April, and the mines were laid on the morning of 8 April, three days later than agreed on 28 March. The next day Germany, carrying out the Weserübung plan, attacked Denmark and Norway. Had the Council’s timetable been kept, the Allies would have laid their mines two days before the German blow. Operation Royal Marine was launched only on 10 May, when the German offensive in the west began, and its effects were lost in the defeat.

Place in the war

The real test of the declaration came in June 1940. After the front had been broken on the Meuse and the evacuation from Dunkirk, the French army was disintegrating. On 13 June at Tours, at the last meeting of the Supreme War Council, Reynaud recalled the undertaking of 28 March and asked Churchill, by then Prime Minister, whether Britain would release France from her obligation not to conclude a separate armistice. Churchill refused and asked him to wait for President Roosevelt’s reply. On 15 June at Bordeaux the majority of the French government, against Reynaud’s wishes, decided to ask London for permission to inquire of the Germans what their armistice terms would be. On the morning of 16 June the British cabinet replied that the undertaking bound the French Republic, not any particular man or government, but agreed to the inquiry on one condition: the French fleet was to sail at once for British ports. In the afternoon London held back these telegrams and offered France an indissoluble union of the two states. The Council of Ministers rejected the plan for union, and that evening Reynaud resigned. The new Prime Minister, Marshal Philippe Pétain, asked the Germans for an armistice the next day, and on 22 June the armistice was signed at Compiègne.

For the British this was a separate armistice concluded in breach of the undertaking of 28 March, and their condition concerning the fleet remained unfulfilled. From this difference of view sprang Operation Catapult: on 3 July 1940 the Royal Navy opened fire on French warships at Mers-el-Kébir, killing nearly 1,300 French sailors. The Vichy government and its supporters replied that the declaration had not been ratified by parliament and that the Prime Minister could not bind the state by it on his own. General Charles de Gaulle, who on 18 June had called on the French from London to fight on and had rejected the armistice, continued the war at Britain’s side.

The formula of 28 March outlived the defeat that had given birth to it. In almost the same words Britain and the Soviet Union undertook, in their agreement of 12 July 1941, neither to negotiate nor to conclude an armistice or peace except by mutual agreement. In the Declaration by United Nations of 1 January 1942, which Poland also signed, all the signatories undertook not to make a separate armistice or peace with the enemy. The principle that a coalition leaves a war only together became one of the foundations of the grand alliance that defeated Germany. In March 1940 it was still the gesture of a new prime minister who wanted to prove to the British and to his own countrymen that France would not give way. Three months later the fate of this promise was decided by men who had not sat at the table in London.