The occupiers grew increasingly harsh as their needs and their setbacks mounted. They had progressively greater difficulty in winning over the occupied nations. Millions of prisoners or war had been taken in the 'lightning wars.' These languished in oflags and stalags. Because the Germans wanted to employ them as cheap manual labour, they freed only very few, and sometimes, as in the case of the Dutch prisoners, took them back. They used extreme measures to bring prisoners to heel. Because Soviet Russia had not signed the Geneva Convention the Germans felt free to deal the crudest treatment out to Soviet prisoners.