The Russian Emperor Alexander I, after concluding the 1807 Treaty of Tilsit with Napoleon, had written to the Swedish King Gustav IV Adolf on September 24, 1807, informing the king that the peaceful relations between Russia and Sweden depend on Swedish agreement to abide by the limitations of the Treaty of Tilsit, which in practice means that Sweden will be been required to follow the Continental System.

The king, who views Napoleon as the Antichrist and Britain as his ally against Napoleon's France, is apprehensive of the system's ruinous consequences for Sweden's maritime commerce.

He instead enters into negotiations with Britain in order to prepare a joint attack against Denmark, whose Norwegian possessions he covets.

In the meantime, the Royal Navy had attacked Copenhagen and the Anglo-Russian War had been declared.

Referring to the treaties of 1780 and 1800, the emperor had demanded that Gustav Adolf close the Baltic Sea to all foreign warships.

Although he reiterated his demand on November 16, 1807, it had taken two months before the king responded that it is impossible to honor the previous arrangements as long as the French are in control of the major Baltic ports.

King Gustav Adolf does this after securing an alliance with England on February 8, 1808.

Meanwhile, on December 30, 1807, Russia had announced that should Sweden not give a clear reply Russia would be forced to act.

Although most Swedish officers are skeptical about their chances in fighting the larger and more experienced Russian army, Gustav Adolf has an unrealistic view of Sweden's ability to defend itself against Russia.

In Saint Petersburg, his stubbornness is viewed as a convenient pretext to occupy Finland, thus pushing the Russo-Swedish frontier considerably to the west of the Russian capital and safeguarding it in case of any future hostilities between the two powers.

The situation is problematic for Sweden, since it once again faces both Denmark and Russia as potential enemies requiring the Swedes to split their forces.

The king thinks it impossible to defend Finland should the enemy attack during the winter and chooses largely to ignore the repeated warnings of the Russian threat he had received in early 1808.

Most of the Swedish plans assume that warfare will be impossible during winter, disregarding the lessons from recent wars.

In addition, several new good roads have been built into Finland, greatly reducing the earlier dependency on naval support for any large operation in Finland.