Modern historians frequently tend to view the battle of Poltava as the beginning of a dramatic change in European history, i.e. the event which broke the back of the Swedish empire and signalled the rise of Russia.
This was not necessarily how the battle later was perceived by the surviving Swedes. Per Adlerfelt (1680-1743), in 1709 a captain in the Life Guards, was in 1739 a Councillor of the Realm and a supporter of the plans to send troops to Finland for the purpose of putting pressure on the Russian government. On 31 August he wrote to Carl Gustaf Tessin, stating that 6,000 men were about to be transferred to Finland. These were under the command of Major General Buddenbrock and Colonels Didron, Pahlen, Silfversparre and Wrangel (all veterans of the GNW and a couple also participants in the campaign of 1708-1709).
When these reinforcements arrived in Finland, Aderfelt wrote, the army would number 20,000. This would make it stronger than any army Charles XII had commanded in battle against the Russians. As God had always used to help the Swedes this would hopefully continue.
The decision had been kept very secret, so if everything worked out the arrival of this force in Finland would make a profound impression in Saint Petersburg. The Russian envoy had not been in Stockholm on the day the orders went out. He had not discovered anything until three days later. The envoy had been profoundly stunned and not sent his first report until the next day. There was great enthusiasm among the officers and the soldiers, Adlerfelt ended his report.
Source: Riksarkivet, Ericsbergsarkivets autografsamling, Vol. 2