When a person country or thing is stronger, they take the land, money, pussy, or home of the weaker entity. This is called 'Invasion'. It has recently lost popularity due to nuclear armaments and the generally shitty attitude it denotes. Still a popular hobby in some ghettos (carjacking, home invasion) and for certain world leaders like Vladimir Putin or almost any U.S. Presidents.
Also applicable when you tap a girl but I wouldn't tell her that you call it that.
"I invaded that puss like it was 1939 again bro!"