Both the Soviets and the Western allies worked very hard to look the other way. I'll quote the article again:
> "Nor did the Soviets acknowledge the extent of the suffering. State broadcasts told of ‘hardship’ and ‘shortage’ – not ‘starvation’ and never ‘famine’"
That's not made up and I was merely highlighting and connecting some dots that the article didn't, but, the main gist is right there. The Soviets covered it up because Stalin only half-heartedly approved supplying the city, they evacuated works of art, but didn't evacuate the people. They didn't leave stores of supplies in the city either. That is why they didn't jump on the radio and told the whole world about atrocious starvation going on there - because they knew they were complicit. Only later after the war when they had a chance to get all their ducks in a row, so to speak, they absolved themselves of any wrongdoing and told everyone that it was all just the Germans.
In case you mean Soviet era school books in the West, that is even more interesting. Why didn't they talk about it? Because it was terribly inconvenient. Stalin was "Uncle Joe", and during the war he was just a confused, fumbling grandpa caught by surprise. But we helped him win the war. If we supported and supplied someone who was starving and killing his own people by the millions, what does that make us? That raises some questions. Britain, for instance, got into WII, to save Poland. But in the end they gave it to Stalin essentially. That's not a happy story to tell the kids, either. The fumbling and confused "Uncle Joe", somehow smartened up and became a cunning fox who tricked us at the end and took control of Poland for decades to control and oppress its population, along with many other countries.