That momentous resolve was formed on or just before July the 16th, in consequence of news that had arrived from Memel and Tilsit. The exact purport of that news, and the manner of its acquisition, have been one of the puzzles of modern history. But the following facts seem to furnish a solution. Our Foreign Office Records show that our agent at Tilsit, Mr. Mackenzie, who was on confidential terms with General Bennigsen, left post haste for England immediately after the first imperial interview; and the news which he brought, together with reports of the threatening moves of the French on Holstein, clinched the determination of our Government to checkmate the Franco-Russian aims by bringing strong pressure to bear on Denmark. To keep open the mouth of the Baltic was an urgent necessity, otherwise we should lose touch with the Anglo-Swedish forces campaigning against the French near Stralsund.[160] Furthermore, it should be noted that Denmark held the balance in naval affairs. France and her allies now had fifty-nine sail of the line ready for sea: the compact with the Czar would give her twenty-four more; and if Napoleon seized the eighteen Danish and nine Portuguese battleships, his fighting strength would be nearly equal to our own.[161] Canning therefore determined, on July 16th, to compel Denmark to side with us, or at least to observe a neutrality favourable to the British cause; and, to save her honour, he proposed to send an irresistible naval force. "Denmark's safety," he wrote on July 16th, "is to be found, under the present circumstances of the world, only in a balance of opposite dangers. For it is not to be disguised that the influence which France has acquired from recent events over the North of Europe, might, unless balanced by the naval power of Great Britain, leave to Denmark no other option than that of compliance with the demands of Bonaparte."[162] _A balance of opposite dangers!_ In this phrase Canning summed up his policy towards Denmark. Threatened by Napoleon on the land, she was to be threatened by us from the sea; and Canning hoped that these opposite forces would, at least, secure Danish neutrality, without which Sweden must succumb in her struggle against France. That some compulsion would be needed had long been clear. In fact, the use of compulsion had first been recommended by the Russian and Prussian Governments, which had gone so far as to include in the Treaty of Bartenstein a proposal of common action, along with England, Austria and Sweden, _to compel Denmark to side with the allies against Napoleon_.[163] To this resolve England still clung, despite the defection of the Czar. In truth, his present conduct made the case for the coercion of Denmark infinitely more urgent.