of the loyalty of naturalized citizens, leading to an increase in denaturalization; nearly all belligerents used denaturalization. In many cases, political dissidence (especially Communist beliefs) or suspected sympathy with an enemy country was the reason for denaturalization, although in practice denaturalization primarily targeted people based on their birthplace. Denationalization laws adopted as an emergency measure during the war persisted afterwards.

The height of denaturalization was in the first