1. Who is the aggressor
The obvious answer seems to be that it is Russia, but that is far from the whole picture. At the end of the Cold War, as agreed with the western powers, Russia disbanded the Warsaw Pact, its military alliance. But the United States and NATO broke their word to Russia, by adding most of Eastern Europe and the Balkan states to their own military alliance, and by building military bases along Russia's southern border. Ever since the end of the Cold War in 1991, the European Union (EU) and NATO have been intent on surrounding Russia with military bases and puppet regimes sympathetic to the West, often installed by 'colour revolutions'. In military expenditure, the US and its NATO allies outspend and outgun the Russian state many times over.