"The world has changed in a negative way," Defence Minister Peter Hultqvist told Swedish broadcaster SVT.
He cited the rearmament of Russia, the country's annexation of Crimea in Ukraine, and the armed conflict in eastern Ukraine as justification for the re-training plans.
The move will mean that around 7,500 people who have served in the Swedish army since 2004 may be called in for a month of re-training.
"The armed forces will be able to carry out fully-manned war preparations which will result in increased operational capacity," Hultqvist explained.
Karlis Neretnieks, a retired major general and the former president of Sweden's National Defence College, was pleased with the news.
"I am extremely happy about this decision. The Armed Forces have had really big problems recruiting enough people on a volunteer basis," he told The Local.
"We'll be able to call on these former conscripts and then carry out exercises with full units - resulting in a more
efficient
and higher level of training."
He added that the move was a positive signal for the Swedish public.
"The environment in the Baltic states and the Baltic Sea is getting a bit nasty, a bit unpleasant, and this move is a good signal to show that the Swedish government has reacted to the developments," he said.
"It's also a good signal to our neighbours that Sweden is concerned. People in countries like Poland, for example, have complained that Sweden hasn't seemed to be reacting to what's been going on."
Neretnieks added that Thursday's announcement was interesting from a political perspective with a fresh set of elections looming in March.