 Complete the following phrase:  The Communist Party was banned in 1941 under the Defence of Canada Regulations and Buck and other prominent Communist leaders were forced underground and ultimately into exile in the United States because of their support for the pact between Hitler and the USSR; both parties mutually invaded Poland which sparked the Second World War. Like supporters and immigrants from Axis countries, communists were considered in collusion with Hitler and all suspected of strongly supporting this alliance were interned under the War Measures Act. The political environment only began to change with the 