The British guarantee to Poland

On 31 March 1939 the British Prime Minister, Neville Chamberlain, declared in the House of Commons that in the event of any action which clearly threatened Polish independence, and which the Polish government accordingly considered it vital to resist with its national forces, His Majesty’s Government “would feel themselves bound at once to lend the Polish Government all support in their power”. He added that the French government had authorised him to state that it took the same position. It was the first peacetime guarantee that Britain had given to a state in Eastern Europe, and at the same time the end of the policy of concessions to Hitler which the same Chamberlain had taken to its height at Munich six months earlier. It is usually described as a guarantee of “Polish independence”, and the wording is precise: Britain guaranteed Poland’s independence, not its borders, which mattered where Danzig was concerned.

The end of illusions: March 1939

The turn in British policy was brought about by the events of mid-March. On 15 March Germany occupied Bohemia and Moravia, and the next day Hitler turned them into a protectorate. For the first time he had seized a country not inhabited by Germans, which robbed of all meaning the argument of self-determination on which appeasement had rested. Chamberlain’s first reaction in the Commons was restrained, but under pressure from public opinion and his own cabinet he asked, in a speech in Birmingham on 17 March, whether this was the end of an old adventure or the beginning of a new one, and whether it was a step towards an attempt to dominate the world by force. He announced that Britain would resist any such attempt with all its strength.

On the same day the Romanian envoy in London, Virgil Tilea, warned the Foreign Secretary, Lord Halifax, that Germany was presenting Romania with an economic ultimatum. The report turned out to be exaggerated, and a few days later Romania signed an economic agreement with the Reich, but in London it created the conviction that action had to be taken quickly. On 20 March the British government proposed to France, the USSR and Poland a joint four-power declaration that, should the independence of any European state be threatened, they would immediately consult on joint resistance. On the same day Germany demanded that Lithuania hand over Klaipėda, and on 23 March it took the town.

The Foreign Minister, Józef Beck, did not want to join the declaration. Since the days of Piłsudski it had been a principle of Polish policy not to side with either of its great neighbours against the other, and a joint document with the USSR would have been read in Berlin as taking part in the encirclement of Germany. Beck also feared that Moscow would demand the right to enter Polish territory. Poland was, moreover, under direct pressure at that very moment: on 21 March Ribbentrop renewed his demands for Danzig and an extraterritorial route across Pomerania, and on 23 March Poland carried out a secret emergency mobilisation of part of its forces. On 24 March the ambassador in London, Edward Raczyński, passed Beck’s counter-proposal to Halifax: a confidential bilateral Polish–British agreement on consultation. On 26 March Poland rejected the German demands, and Ribbentrop replied with threats.

The decision

The British soon abandoned the plan for a four-power declaration and began to think about commitments to Poland and Romania. In the last days of March warnings poured into London that Germany was preparing to strike at Poland, perhaps within days. A particular impression was made by the account of Ian Colvin, the Berlin correspondent of the News Chronicle, who spoke to Halifax and then to Chamberlain on 29 March. The rumours of an imminent attack were untrue, as Hitler had not yet decided on war, but in the atmosphere after the fall of Prague no one in London wanted to risk another surprise. Some historians stress that the British government also feared that Poland, left to itself, would give way to Germany, as Czechoslovakia had been forced to do before it.

On 30 March the cabinet approved the text of the statement. The British ambassador in Warsaw, Sir Howard Kennard, then presented it to Beck and asked whether Poland would accept it. Beck, as he later recalled, made up his mind “between two flicks of the ash from my cigarette”. France, bound to Poland by the alliance of 1921, joined without hesitation, even though its Foreign Minister, Georges Bonnet, was among those in favour of withdrawing from commitments in Eastern Europe.

On the morning of 31 March the opposition asked the Prime Minister about the situation in Europe. In the afternoon Chamberlain read out the statement. He began by saying that the government had no official confirmation of the rumours of a planned attack on Poland, and recalled that he favoured settling disputes by free negotiation. He then explained that consultations with other governments were in progress and that “in the meantime”, until they were concluded, Britain would give Poland every assistance should its independence be clearly threatened and should Poland decide to defend itself. An assurance to that effect had been given to the Polish government.

What Britain guaranteed

The statement was short and provisional in nature. Its most important feature was that it left it to Poland to decide whether a threat was serious enough to resist. In practice it was Poland, not London, that could decide whether Britain went to war. Critics later pointed out that for the first time in history a British government had placed so momentous a decision in the hands of a foreign state.

At the same time, the guarantee concerned Poland’s independence, not its territorial integrity. The next day, 1 April, a leading article in The Times stressed that the new commitment did not bind Britain to defend every inch of Poland’s present frontiers, but its independence. This was received with alarm in Warsaw, as the article looked like a signal that London still saw room for compromise over Danzig. The British government gave assurances that the newspaper did not express its position, but in the months that followed the question of the Free City did indeed remain the most awkward point of the commitment for the British.

In the debate on 3 April Chamberlain spoke of a new epoch in British foreign policy. Winston Churchill supported the guarantee but urged that the Soviet Union be brought in. David Lloyd George warned that without the USSR Britain was taking on a commitment it would be unable to fulfil, since it had no way of reaching Poland with help. The dominions also had doubts: representatives of Canada and South Africa let it be known that a war over Danzig would meet with little understanding among them.

From guarantee to alliance

At the beginning of April Beck came to London, having been invited before the guarantee was announced. After talks with Chamberlain and Halifax a communiqué was issued on 6 April: the two countries were prepared to conclude a permanent agreement on mutual assistance to replace the provisional, unilateral assurance. Until then Poland undertook to assist Britain on the same terms on which Britain had promised to assist Poland. The agreement was to cover any threat, “direct or indirect”, to independence. Beck also avoided what he had feared: he refused to extend the new commitments to Romania, so as not to antagonise Hungary, and would not agree to any tie between Poland and the Soviet Union.

The guarantee to Poland was the first of a whole series of British commitments. After the Italian ultimatum and Italy’s invasion of Albania on 7 April, Britain and France gave guarantees to Romania and Greece on 13 April, and on 12 May Britain signed a declaration of mutual assistance with Turkey. At the end of April the British government announced the introduction of conscription, the first in peacetime in the country’s history. At the same time London and Paris opened talks in Moscow on an alliance with the USSR, which dragged on throughout the summer.

Hitler’s reaction

Hitler received the news in a fury. According to accounts passed on from the circle of the head of military intelligence, Admiral Wilhelm Canaris, he shouted that he would brew the British a devil’s potion. On 1 April at Wilhelmshaven, at the launch of the battleship Tirpitz, he made a speech against the policy of encircling Germany. On 3 April the head of the OKW, Wilhelm Keitel, issued a directive on preparing war against Poland under the code name Case White (Fall Weiss), with readiness from 1 September. On 28 April, in the Reichstag, Hitler repudiated the declaration of non-aggression of 1934, citing the Polish–British agreement as his reason, and with it the naval agreement of 1935 with Britain. The guarantee did not deter him from war. It did, however, convince him that if he wanted to fight Poland without a war on two fronts, he had to come to terms with Moscow or count on the British and French backing down at the last moment, as they had at Munich. His Foreign Minister, Joachim von Ribbentrop, assured him to the very end that this would happen.

What the guarantee was worth

The guarantee had one fundamental weakness: Britain could not help Poland directly. It had no common border with Germany and no large army, and the Baltic was in practice closed to the Royal Navy. Help could come only in the form of a French offensive in the west and action by the air forces. In May in Paris the Minister of Military Affairs, General Tadeusz Kasprzycki, and the Commander-in-Chief of the French Army, General Maurice Gamelin, signed a protocol in which France promised to launch an offensive with its main forces no later than the fifteenth day of mobilisation. The British held staff talks with the Poles but made no specific military promises. Agreement on financial aid for rearmament was not reached until early August, and the credit was many times smaller than Poland had asked for.

Historians still argue over how to judge the decision of 31 March. Some, such as the British historian A.J.P. Taylor and the military theorist Basil Liddell Hart, considered it rash: Britain had promised something it could not deliver, had hardened Poland’s refusal to yield to Germany, and had at the same time strengthened the position of the USSR, which from then on both the British and Hitler had to reckon with. On the Polish side a similar criticism was made by the writer Stanisław Mackiewicz, who called the acceptance of the guarantee one of the most tragic decisions in Polish history. Other scholars point out that Poland had no intention of giving way in any case, and that without the guarantee Hitler could have defeated it in isolation and then turned against the West in conditions even more favourable to himself. In this interpretation the guarantee was not meant to save Poland but to draw a line whose crossing would mean a great war. Whether it deterred or provoked Hitler remains an open question. What is certain is that it did not stop him – but also that without it 1939 would have looked quite different.

What came of it

The provisional guarantee of 31 March was turned into an alliance only in the last week of peace. On 23 August 1939 Vyacheslav Molotov and Ribbentrop signed a non-aggression pact in Moscow, and two days later, on 25 August, Raczyński and Halifax concluded the Polish–British treaty of alliance in London. Its secret protocol specified that the “European Power” against whose aggression the parties were to defend themselves was Germany. The news of the alliance, together with Mussolini’s refusal, led Hitler to postpone the attack planned for 26 August.

On 1 September 1939 Germany invaded Poland. Britain and France, after two days of hesitation and attempts at mediation, declared war on Germany on 3 September. In this sense the guarantee of 31 March kept its word: the war against Poland became a European war, and in time a world war. The promise of all support in Britain’s power did not, however, translate into military help in September. France confined itself to a token Saar offensive, the RAF dropped leaflets over Germany, and in the west the Phoney War began. When the Red Army entered Poland on 17 September, London took the view that its alliance obligations did not cover this. For the Poles, the commitment of spring 1939 became both a source of hope, which allowed the authorities and the soldiers to continue the fight at Britain’s side throughout the war, and a source of bitterness, symbolised by Yalta and the country’s post-war fate.