The most important weapon on display at yesterday's Victory Day parade in Moscow wasn't a warplane, a battle tank, or a missile launcher.
It was a human weapon. And it can be launched by Vladimir Putin alone.
Amid all the military hardware and soldiers on Red Square, were some 400 members of Russia's new national guard, an elite Praetorian force that will number 180,000 and report directly to Putin.
It marched in formation past the viewing platform. It pointedly saluted the Kremlin leader.
And in the process, it sent a stark message to Putin's opponents, both real and imagined.
The National Guard, of course, will be a useful tool for the regime to put down any civil unrest that may arise as the economy stagnates and living standards plummet.
But its real purpose -- and the likely reason it was on display yesterday -- was to send a message to the elite that Putin is prepared to meet any internal challenge to his rule, any attempt at a palace coup, with force.
And the fact that Putin feels he needs such a force, and one run by his uber loyal former bodyguard Viktor Zolotov, shows that his long rule is entering a new phase.
An isolated phase. A paranoid phase.
It's a phase that almost all authoritarian regimes eventually enter.
The phase when the great and dear leader is left all alone with his power -- and with his fear.