Whataboutsim is a favorite tactic of trolls and my ambassadors & politicians (sorry for repeating myself)
Allow me to begin with a joke from the good old days of the Soviet Union.
A Soviet car salesman and an American argue which country makes better cars. After some back and forth the American asks: "How many decades does it take an average Soviet man to earn enough money to buy a Soviet car?" After a thoughtful pause, the Soviet replies: "But you are lynching black people!"
You see, the original argument (that US cars are better) is left unaddressed. You cannot critisize us as you are not perfect yourself.
It also has a much more sinister aspect to it if you look carefully to the argument, as the BBC recently found out. When a Russian general was asked about civilain casulaties resulting from the Soviet invasion of Afghanistan (of which there were around a million), he responded that the British could not critisize Russia as people (around 3000) had been killed in Ireland. So it is the the position of a general in the Russian army that a million Afghan deaths is the same as the deaths of 3,000 white people.
And you'll note the BBC never challenged him on this. Russian atrocities in Afghanistan neatly deflected.
A proper definition of "Whataboutism" is therefore in order, so, lifted directly from Wikipedia, here it is.
It represents a case of tu quoque or the appeal to hypocrisy, a logical fallacy which attempts to discredit the opponent's position by asserting the opponent's failure to act consistently in accordance with that position, without directly refuting or disproving the opponent's initial argument.
In more recent times your Prez sees arguments that go a lot like this.
Troll: "The USA cannot critisize Russia for invading Ukraine as it invaded Iraq"
Sane Person: "So you're saying Russia is at best only doing the same evil as the USA?"
Troll: "......fuck...." (they'll get mad and call you names at this point)
So, the troll's logic is as follows
If the US does something wrong it allows Russia to do the same thing while, strangely, not also being wrong. It should be noted that the start date for the USA's misdeeds is in the 1600s whereas Russia's is tomorrow. For example, the US can't criticize Russia for Crimea cos it took land from native Americans. Our annexation of Crimea is not the same even though we've just implied it is.
By now you are used to it. There'll be more of it as we don't have much else. So, what do you do about it?
It really helps the troll if you try to engage with them on their terms. They would like you to forget the original point, for example that you (who might or not be an American) cannot criticise the fact that Russian troops are in Ukraine (hint: they often forget that there are not any there) because the US invaded Iraq. They want to argue about Iraq and not about our invasion of Ukraine.