Britain declares war on Finland

On 6 December 1941, Finland’s Independence Day, the British government announced that a state of war existed between Britain and Finland, with effect from one minute past midnight Greenwich time on 7 December. It took the same decision with regard to Hungary and Romania. This was the culmination of the pressure that Joseph Stalin had been putting on London since the summer, and of the ultimatum delivered to Helsinki at the end of November. Since the Finns had not undertaken to stop fighting the USSR by the deadline of 5 December, the word that Winston Churchill had given Stalin had to be kept.

The date of this event is given differently in the literature: 5 December (when the deadline expired), 6 December (when the decision was announced) or 7 December (when the state of war began), and some tallies even move it to 3 December, the original deadline of the ultimatum. All of them refer to the same decision. Often only Finland is mentioned, but the declaration covered three states that had joined Germany’s war against the Soviet Union in the summer of 1941.

Three states “on the same footing”

The government gave its official explanation in the House of Commons on 10 December. The Parliamentary Under-Secretary at the Foreign Office, Richard Law, recalled that Finland had maintained from the outset that it was waging a purely defensive war, but had been unable or unwilling to avoid full association with Germany. On 28 November, in agreement with the Soviet government, Britain had given it a “last opportunity” to withdraw from hostilities. Similar notes, he stressed, had been sent to the governments of Romania and Hungary, “whose cases have throughout been treated on the same footing as that of Finland”. The required assurances had not been received.

Each of the three states was in a different position. Finland had entered the war against the USSR on 25 June, arguing that it was fighting separately, for its own security, while Britain had been Moscow’s ally since the agreement of 12 July. Marshal Ion Antonescu’s Romania had gone to war alongside Germany on 22 June 1941, recovered Bessarabia and northern Bukovina, and in October, after a long siege, its army had taken Odessa, where a massacre of the Jewish population soon followed. Antonescu went further than any of Hitler’s allies and had no intention of stopping at the old frontier. The Hungary of the Regent, Miklós Horthy, and Prime Minister László Bárdossy had declared war on the USSR on 27 June, after a mysterious air raid on Kassa (Košice). Its Mobile Corps had reached as far as the Donets in the autumn and in November, exhausted, returned home, leaving occupation divisions in the rear of the front. For London the calculation was simple: Hungary and Romania were already subject to the British blockade and diplomatic relations with them had been broken off earlier, so in practice the declaration changed little. Churchill had long hesitated over whether it would be better to leave Budapest and Bucharest a door open to change sides, but Stalin wanted a clear declaration and would not give way over Finland.

The dominions

Britain declared war on behalf of the whole colonial empire and India, but since the Statute of Westminster the self-governing dominions had decided for themselves. They nevertheless followed London within two days. William Lyon Mackenzie King’s Canada and Peter Fraser’s New Zealand proclaimed a state of war with Finland, Hungary and Romania on 7 December, and Australia and the Union of South Africa on 8 December. In Australia the proclamation was signed by the Governor-General, Lord Gowrie, on the advice of John Curtin’s government; according to Churchill’s letter to Stalin, Australia was the only dominion that had no reservations about the Soviet demand. In South Africa the decision was taken by Jan Smuts’s government. Those same days, however, brought the Japanese onslaught in the Pacific, and a minor paper war with three Eastern European states vanished in the shadow of the great war in Asia.

Finland halts

In Finland itself the decision came as no surprise. Marshal Carl Gustaf Emil Mannerheim had replied to Churchill on 2 December that he would not halt operations until his troops had reached positions that would ensure the country’s security. In practice he was already close to that goal. At the beginning of September Finnish troops in East Karelia had reached the Svir, the river linking Lake Onega with Lake Ladoga, and seized bridgeheads on its southern bank. The Germans expected the Finns to push on and join hands with the troops of Army Group North, which had taken Tikhvin in November, thereby closing a second, outer ring around Leningrad. Mannerheim refused. His troops turned north, towards the White Sea–Baltic Canal, and at the beginning of December took Medvezhyegorsk and Povenets. Soon afterwards the Marshal halted the offensive, and the Continuation War entered a positional phase that was to last nearly two and a half years.

In the Gulf of Finland the Russians were just evacuating the base on the Hanko peninsula, and before Moscow the Red Army was launching the counter-offensive that was to transform the picture of the war in the East. In Helsinki, what Churchill in his letter to Mannerheim had called a good pretext for stopping was already a fact, but the government had no intention of announcing it in the form that London and Moscow demanded, nor of withdrawing from the East Karelia it had occupied.

A war on paper

The Anglo-Finnish war remained a war without fighting. The British had neither reason nor means to attack Finland, nor the Finns to attack Britain. British interests in Helsinki continued to be represented by the Americans. All 227 British volunteers who had come to fight for Finland during the Winter War had left the country, Law reported, by December 1941. In Hungary and Romania even less changed, since there had been no British diplomats there for a long time. The real consequences were political. Stalin got what he had been demanding since the summer: proof that Britain stood by him without reservation against all his enemies. A few days later Anthony Eden flew to Moscow, and Stalin demanded that he recognise the Soviet frontiers of June 1941, including the border with Finland drawn in the Moscow Peace Treaty.

The United States took a different course. After entering the war, it did not answer the declarations of war by Hungary, Romania and Bulgaria with declarations of its own until 5 June 1942. It never declared war on Finland, although it broke off diplomatic relations with it in June 1944.

Place in the war

The declaration of 6 December ensured that Finland, Hungary and Romania ended the war as defeated enemies of the Allies. Romania changed sides in August 1944; Finland signed an armistice with the USSR and Britain in Moscow on 19 September 1944; Hungary concluded an armistice in January 1945, while Budapest was under siege, although part of the Hungarian army fought alongside the Germans until the end of the war. All three states signed peace treaties with the Allies in Paris on 10 February 1947. Finland, alone among them, was not occupied and kept its democratic system, but it had to cede to the USSR the territories lost in 1940 and Petsamo, lease it a base at Porkkala and pay reparations. The fate of the states on which Britain had declared war at the request of its Soviet ally was ultimately decided not in London but in Moscow.