No, if you were old enough when the Berlin Wall came down and had any interest in world news, you would know about Leningrad and St. Petersburg. I guess if you're young enough, that's not part of the zeitgeist for you. I'm kind of surprised you'd heard of Leningrad, to be honest.

For someone with Trump's upbringing, not knowing this is either dementia or he's always been an idiot. Given when he was running in 2016 he didn't know the difference between Hezbollah and Hamas, I would lean toward idiot.

You’re not the president

Probably something you’d only know if you are actually a Russian citizen, or live there.

It's generally known. It's not an obscure fact, at least outside of the USA. I agree with you that this is weak evidence of dementia. But since this is a basic fact any politician dealing with Russia should know, it's at least evidence (if we needed any) that Trump is not qualified for the job of President.

I don't know, I would say after the fall of the Soviet Union its renaming was fairly common knowledge if you lived through that (even outside the former Soviet States)

I had to look it up because my brain was insisting that Vladivostok changed names (it didn't, shut it scumbag brain!)

List of Russian city name changes. More than I expected:

https://en.m.wikipedia.org/wiki/List_of_renamed_cities_and_towns_in_Russia

Or you know... If you're the president of the USA.

The... the fucking president of the United States should know about St. Petersburg. I don't care if it's senility or not bothering to read or learn anything since the 1980s.

YOU don't have to know. But a president not knowing is terrifying. He has to have at least some knowledge of the countries he's dealing with. It's his job.

Most Americans, if you ask about "St. Petersburg" are going to go "Florida?"