Finland was distinct from Russia

To the traveller without special credentials, the short journey from Haparanda to the railway-car at Tornea which is to bear him onwards must have been almost a foretaste of the Valley of the Shadow of Death. Even for the members of a military mission with "red passports," whose advent had been announced, it was one prolonged agony; and it would probably have been even worse when the intervening estuaries were not frozen over and when one had to take the ferry. All the formalities had to be gone through twice over because there was an island, although the Russian officials were the very pink of courtesy. One learns a great deal of geography on journeys of this kind; we had not realized the extent to which Finland, with its special money, its special language, and its special frontier worries, was distinct from Russia. The train took three days and nights between Stockholm and Petrograd, and one was supposed to fetch up at the terminus somewhere about midnight; but it always took two or three hours to get through the frontier station between Finland and Russia at the last moment, with the result that one might arrive at the capital at any hour of the early morning.

Charles Edward Callwell: Experiences of a Dug-out, 1914-1918