Jörgen Elfving is a former lieutenant colonel with a background in military intelligence with a focus on Russia. He has also written a book on Russian military tactics and continuously follows developments on the battlefield.
"What has now been expanded on the Russian side is very odd," he says.
In the military-tactical rule books, both in Russia and in the West, it is no longer straight lines that are the model but instead a system of various small "islands".
The difficulties of linear defense
He does not know why the Russians have chosen a different method, they have not given any explanation. The linear defense makes it more difficult to make up for lost terrain and face an attacker.
Elfving speculates that simplicity alone has made the decision.
"It's basically just shoveling up a ditch.
'Tough task' to break through Russian defense lines
At the same time, he says that one should not underestimate the difficulties of breaking through the Russian defense lines.
"It will be a very tough task for the Ukrainian side.