S: (v) invade, occupy (march aggressively into another's territory by military force for the purposes of conquest and occupation) "Hitler invaded Poland on September 1, 1939"
S: (v) attack, assail (launch an attack or assault on; begin hostilities or start warfare with) "Hitler attacked Poland on September 1, 1939 and started World War II"; "Serbian forces assailed Bosnian towns all week"
S: (v) contend, fight, struggle (be engaged in a fight; carry on a fight) "the tribesmen fought each other"; "Siblings are always fighting"; "Militant groups are contending for control of the country"