On Monday, tabloid Expressen reported new infringements on Swedish airspace. The Swedish Armed Forces confirmed a French plane entered Swedish airspace on Saturday, though initial media reports claimed it was Russian.
The news came just days after Sweden confirmed that a submarine entered Swedish waters in October. The submarine is widely believed to have been Russian, though that has not been confirmed by the government or the Swedish Armed Forces.
Peter Mattsson, a senior lecturer at Sweden's National Defence College, is convinced that the submarine was Russian.
"This is part of a pattern and designed to affect our population and our politicians. It is also a test of the Swedish Armed Forces," Mattsson told Radio Sweden.
According to Mattsson, who has specialised on Russian defence, these moves are part of a new, psychological warfare.
"The Russians call this 'the sixth generation of warfare' or 'non-contact warfare'," Mattsson said. "The military is not the main objective. Instead, the main objective is the society itself."
Asked why Russia would be interested in this, Mattson said that after 20 years of Sweden significantly cutting its defence capabilities, the Russian government is concerned about the weakened Swedish military.
"If we don't have [a strong defence], then we must get help from someone else. And that someone else is - in the Russian view - Nato. If the Russians can show that we have weak defence capabilities, then the effect could be that we could get more military spending in the budget and that increases our ability to defend ourselves," said Mattson.
The Russians are interested in a stronger Swedish defence because "they don't want to have Nato bases in Sweden. That would be a nightmare for them."