This is a good book on the topic. Interestingly, the work of deporting Soviet Koreans to Kazakhstan was entirely done by ethnic Korean NKVD officers who deported themselves as well.
In general Stalin distrusted any ethnic group whose homeland lay outside of Soviet borders & was hostile to Soviet power.
The fear was that ethnic Koreans acting as spies for Japan could inflitrate Soviet Korean communities in the Far East, which remained on of the most insecure and heavily guarded regions of the USSR from its inception to dissolution.
Poles were one of the most persecuted ethnic groups under for this very reason, this partially explains the turn to "anti-antisemitism" after Israel was founded and aligned itself with Western powers
"Love everyone"
Translation from ีธiึึะตrbabble to human:
"Hello im a shitskin living in a mudhut with no tap water;
Let me squat into europe, get a government job and make whites pay for my welfare"