Rubuta ci gaba don wannan sakin layi - Applegate ya haɓaka dabarun da aka bayyana a cikin littafin yayin aikinsa tare da William E. Fairbairn, wanda a baya ya haɓaka nasa dabarun yayin aiki ga 'Yan Sandan Birnin Shanghai daga 1907 zuwa 1940. Fairbairn ya yi amfani da fasahar yaƙi ta kasar Sin, wanda ya sauƙaƙe kuma ya dace da bukatun horar da 'yan sanda a cikin ɗayan biranen da ke fama da aikata laifuka a duniya, saboda tarihin aikata laifuka da suka shafi cinikin opium, tawaye
, da kuma ayyukan 'yan daba Triad. Sakamakon shi ne ci gaban Defendu, wanda aka fi sani da farko na abin da aka sani da zamani na zamani. Hanyoyin Applegate sun dogara ne akan Fairbairn's Defendu, wanda aka inganta tare da ra'ayoyi daga ma'aikatan OSS waɗanda suka sanya fasahohinsa cikin aiki a lokacin Yaƙin Duniya na II.