I'm sorry if this seems like a dumb question, but my history education was severely lacking and there is a lot I don't know
From what I understand, the US and Russia are both capitalist but they both oppose each other, while there seems to be greater cooperation between the US and EU + Britain. Why's this the case? I would extend this question out to China but from what I understand from the struggle sessions is that we don't fully know yet where China stands (feel free to correct me)
Again I'm sorry if this all sounds dumb, I'm very ignorant of history and of the world outside the US
They are competitors in terms of oil production and in weapons sales.
The US and Russia were plenty in line during the Yeltsin years as he followed what the US and Oligarchs in Russia wanted but as far as I understand the split in foreign policy that we still see between Russia and the US goes back to Putin's unwillingness to support the Iraq War.
There is also a lot of carry over from the cold war. The expansion of NATO into eastern Europe being an especially large part of the tension between the two countries.