President Vladimir Putin told pupils at the start of the school year today that it was impossible to defeat Russia.
He was speaking as Moscow's offensive in Ukraine grinds through its 19th month, and a new curriculum is introduced, which includes operating military drones.
"I understood why we won the Great Patriotic War," Mr Putin said, referring to World War II.
"It is impossible to defeat this kind of nation with this kind of attitude. We were absolutely invincible. And we are the same now," he claimed.
This year, Russian teenagers will learn how to operate military drones.
The curriculum published this week by the education ministry comes after Moscow vowed to reintroduce Soviet-style military training for children.
The drone course will be undertaken by pupils who are aged between 15 and 17.
They will "perform practical tasks on drone piloting" as well as "learn the algorithm to counter enemy drones", according to the curriculum.
The revised military programme also includes a module dedicated to Kalashnikov assault rifles and hand grenades.
The contrast between the back-to-school experiences of Russia's children and those in the country it has invaded were starkly underlined today.
Children in Ukraine's northeastern city of Kharkiv have been living through war for over a year-and-a-half.
Today, they started their new school year underground, to avoid attacks from Russian missiles.
There were reports of bomb threats at schools in the capital Kyiv as the education ministry said that nearly four million students were returning to school, both online and in person.
Ukrainian officials said Russian attacks since the beginning of the invasion in February 2022 had damaged or destroyed thousands of schools.
Andriy Sadovy, mayor of the western city of Lviv, said pupils will be learning to fly drones, releasing a picture of students behind computers.
"This is our new reality," he wrote on social media alongside images of children holding controllers and sitting in front of monitors simulating drone flights.
