The reincarnation of the old USSR. Putin is a former KGB agent who wants nothing more than to return Russia to the "glory days" of the USSR and, slowly but surely, that's what he is doing.
Russia cannot and should not be trusted.
Roger that. They still support our enemies, like Iran.
That would be a mistake, and I don't think Putin is even considering this scenario. The reason is that USSR was formed historically as a massive land grab by Bolsheviks, in early 1920s, when those lands were nothing but dust bowls with a few cattle herders. Then Baltic republics were acquired in 1940's.
Asian republics are a complete writeoff. It was obvious all the time, but the Communist Party tried to rule them with iron fist and drive them, kicking and screaming, into some semblance of a civilized state. That did not last, and after 1990s these places happily reverted to their traditional tribal politics, vendettas, and such.
Baltic states are now well integrated into the EU. They are tiny by population and by land, and they have their own problems, so reconquering them would be impractical.
Putin may want to create the new USSR only around a few relatively civilized countries, like Russia, Belarus and Ukraine. They have 90% of all USSR's industry anyway, and probably 99% of universities. Everyone else would be an irrelevant, useless cannonball on the leg of the new union.
Putin [...] wants nothing more than to return Russia to the "glory days" of the USSR and, slowly but surely, that's what he is doing.
That's fine as long as "glory days" are all about wealth and stability. I don't think he wants, or has any chances, to return Communists to power - they failed in that job and it is clear why. Putin's plans are different. He positions himself as a "good king" with power. This is in part bad and in part good.
With regard to trust, "Nations have no permanent friends and no permanent enemies. Only permanent interests." There is no country on the planet that wouldn't sell you and your interests if that benefits them enough.