Russia and the west are on a collision course over Crimea after Moscow was accused of orchestrating a "military invasion and occupation" of the peninsula, as groups of apparently pro-Russian armed men seized control of two airports. Russian troop movements were reported across the territory. Full story >>
An invasion is the act of an army entering another country by force in order to take control of it. • The German invasion of Poland in 1939 was the kick-off to the six-year long global war.