President Vladimir Putin was shown a simulation of the "nuclear button" but declined to press it on Monday as he toured a vast exhibition of Russian achievements in what looked like a warm-up for an imminent re-election campaign.
Putin was given an explanation of a Soviet nuclear bomb design and shown a mock control panel for launching a nuclear test, before observing images of a blast and mushroom cloud through a viewing window.
Since the start of the Ukraine war, Putin has frequently reminded the West of the size and capabilities of Russia's nuclear arsenal, saying anyone who tried to launch a nuclear attack against it would be wiped from the face of the earth.
He has deployed tactical nuclear missiles in Belarus and shifted Russia's stance on two major arms treaties, while insisting that Moscow is not recklessly "brandishing" atomic weapons or changing its doctrine on their use.
Putin is expected this month to confirm that he will run for another six-year term in March, and Monday's appearance had a distinct pre-election feel.
He was shown with a group of schoolchildren writing a message on a giant whiteboard about his hopes for their future, and selecting from among wishes that children had pinned to a Christmas tree in the hope he could make them come true.
Adding to the flattering tone of coverage, state news agency TASS quoted an Olympic boxing champion, Oleg Saitov, remarking on the strength of Putin's handshake.
Putin, 71, has led Russia as president or prime minister since 1999, when Boris Yeltsin stepped down and made him acting president on the last day of the old millennium.
With six more years in the Kremlin, he would overtake Josef Stalin, who led the Soviet Union from 1924 until 1953, and become Russia's longest-serving ruler since Catherine the Great in the 18th century. Putin was shown a replica of Stalin's office during his exhibition tour.
Confirmation of a re-election bid could come next week when Putin hosts a news conference and phone-in where viewers from all across Russia will have the chance to put questions to him.
The event is being held for the 20th time and normally runs for hours. State TV has been showing preparations for it, with staff in "Team Putin" teeshirts answering phones at call centres to take in questions from the public.
For Putin, the election is a formality if he runs: with the support of the state, the state media and almost no mainstream public dissent, he is certain to win.
Opposition politicians cast the election as a fig leaf of democracy that adorns what they see as the corrupt dictatorship of Putin's Russia. Such elections, they say, often draw in weak candidates to give the pretence of competition.
Supporters of Putin dismiss that analysis, pointing to independent polling which shows he enjoys approval ratings of above 80%. They say that Putin has restored order and some of the clout Russia lost during the chaos of the Soviet collapse.
