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RedGrizzly The French, under Napoleon Bonaparte, had tried invading Russia as well, also failed.
The climate is a major factor but so is the sheer size of the country. The further from home you fight, the wider your front, the longer your supply-lines and the easier it is for the victims to attack your flanks.
For Germany in WW2 though, its turning against Russia gave itself enemies on two major fronts in geographically opposite directions against a single
bloc of allies for the time being.
While both countries were Communist, China and Russia had a very uneasy relationship indeed, and their Amur River border was one of the most heavily watched and guarded in the world. It is still heavily military but the two countries are now on much better terms despite the fall of Communism in Russia.
Their trade with each other has even extended to China building at least one new railway across Mongolia to join the Trans-Siberian Railway*, presumably part of its "Belt Road" initiative whose actions include buying the Greek port of Piraeus, and building facilities in developing countries who can never repay the Chinese "loans" involved.
China is unlikely to even think of trying to take over Russia. She would know she would fail. Her first aim is to take Taiwan, then to become the world's most powerful country. She does not need invade Russia for that, but instead to trade with it - principally buying Russian gas, petroleum and ores. Whilst also supporting a general anti-"West" programme based on commercial advantage, the Internet and naked interference.
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*Trans-Siberian Railway: This is a very busy line, and until the invasion of Ukraine, carrying a lot of goods between Asia and Europe.
Recently China
apparently published a glossy video promoting a "new", non-stop (?) goods-trains only service, all the way from China to Spain. The video ignored the matter of the break-of-gauge between Russian and European railways, and its map showed the line going not South-West to Spain but turning North to terminate in Belgium. Very odd. Perhaps the video was not real even by Chinese propaganda standards, but an elaborate hoax by Persons Unknown.