If it fooled the public, it could easily fool the Russian government. All they know is the film.
False, the USSR had a very active space program of their own. They could pointed their radio telescopes at the moon and found that there was no footage being transmitted from there, or they could inspect the site with their own satellites and even a land mission. They would have also had all the technical knowledge to know whether the mission was possible or not.
To pretend that the USSR - at the time a massive, technologically advanced nation deeply suspicious of the USA - was the equivalent of some chump at home on a sofa is breathtakingly naive.
They see it and assume it is real.
Why would they? They had the technical knowledge and equipment to spot a fake. They had the motive to hope it was fake (imagine the headlines! "USSR humiliates America! Apollo landing proved hoax by Russian moon landing."
They'd get to be first AND humiliate the USA, the propaganda machine would have been running with it for
decades.
OR if they don't believe it, they can't say anything for fear that if it is real, America would know Russia is much further behind technologically.
That doesn't follow.... they figured out the landings were fake which is evidence they are FURTHER behind in technology?!? Being able to do something is generally a sign of technology not lack of it....
Therefore, they don't say Apollo is a hoax because they think that if it is real, they want America to believe that they could do it too.
That doesn't make sense. They never did do it so no one believed they could (their Saturn V equivalent wasn't any good and once they lost the race they lost incentive to go at all). Besides they wouldn't be showing they were any further behind than the USA since they'd have shown the USA couldn't either (they'd really have shown up the Americans by then going too)
OR the American and Russian governments could have been in on it together, which is the theory I lean towards.
WHAT?!?!?!? Why would two arch enemies, fighting multiple proxy wars and trying to show each other up then collude to allow one of them to look like they've won something they haven't? Then knowing the lie wouldn't then betray the other and use that knowledge to disgrace them? What was in it for the ruskies?
So now we have a global international conspiracy, involving multiple countries including opposite sides of the Cold War who each want to nuke the other into oblivion, working together to fool people into thinking one has achieved an arbitrary milestone of considerable propaganda value? They couldn't have worked together to achieve something more meaningful/useful for the ruskies? What has kept them all quiet now that the iron curtain has been down for over two decades?
The problem you now have is that you have a conclusion that you are inventing explanations for as you go, you have no evidence for these explanations and obviously no intent to test them. It has become so fantastical that it is less believable than the alternative, they really did go.
Further, why has Russia not landed on the moon? Why has no other country gone to the moon, and why hasn't America gone back since 1972?
Because its an expensive boondoggle with no lasting economic benefit, little further scientific benefit and little propaganda benefit anymore. That said the Chinese might be going some time in the next decade or two, we'll see (to them it seems to still have some nationalistic posturing value, which is important for their current government).