In the run-up to the war, President Putin urged the outside world not to get involved with the words "it can have consequences greater than any of you have encountered in history."
Russia also conducted a nuclear exercise just before entering Ukraine.
According to Magnus Chistiansson, a doctoral student in military strategies, however, it is unnecessary to worry unnecessarily.
- It is impossible to calculate the probability and I do not understand how one would be less relaxed if it is three percent probability or seven percent probability.
Increased stakes
It is especially if the war does not develop in the direction that Russia wants and Ukraine's resistance is fueled by the West that it can lead to higher efforts from Russia.
- To show that they are prepared to take greater risks than the opponent is a strategy to get them to back away.
It includes a whole arsenal of different weapons, including nuclear weapons, says Magnus Christiansson.
- In the worst case, it may be that the West has to choose between an occupied Ukraine or an escalation.
"Keep calm and carry on"
Concerns about nuclear weapons have also increased at home in the past week.
The number of Swedish searches on the word has increased significantly in the last week and looks to be the highest search listing on Google in ten years.
Magnus Christiansson urges to try to keep calm.
- We have little to learn from our Finnish friends who have lived near Russia for a long time.
Not to get so excited and be aware that there are risks in the relationship with Moscow.
It really is a sign of the times that thing with "keep calm and carry on", he says.