Rubuta ci gaba don wannan sakin layi - A duniya, de Zúñiga ya ga makomar Spain a matsayin wani ɓangare na ƙawance mai ƙarfi tare da Daular Roman Mai Tsarki wanda dangin Habsburg ke mulki, yana maimaita "arbitrista" na zamani Giovanni Botero, wanda ya inganta manufar dangin Habsburg-wanda ke jagorantar mulkin mallaka a duk faɗin Turai. De Zúñiga ya kuma sami tasirin abin da zai faru ga arewacin Italiya da ke ƙarƙashin mulkin Spain idan reshen Austriya na dangin ya gaza a Jamus. De Zúñiga ya shawo kan Philip III ya aika da taimako ga Sarkin sarakuna a Bohemia a shekara ta 1619, wanda ya shiga Spain cikin yakin shekaru talatin (1618-48). A shekara ta 1620, ya taka muhimmiyar rawa wajen aikawa da Sojojin Flanders don taimakawa Imperial, wanda ya kai ga nasarar Mutanen Espanya a yakin White Mountain.
daga baya a wannan shekarar. De Zúñiga kuma yana da alhakin manyan yanke shawara na Mutanen Espanya game da makomar rikici a Netherlands. Hukuncin yaƙi tun daga 1609 ya zama mai tsananin tashin hankali; yayin da de Zúñiga ya gamsu da cewa nasarar soja kai tsaye a kan Yaren mutanen Holland ba zai yiwu ba, a shekara ta 1619 ya yanke shawarar cewa sabunta tashin hankali na iya ba da damar tattaunawa da za ta haifar da yarjejeniyar da ta fi dacewa da Mutanen Espanya. Ya kasance babban alhakin sabunta yakin a 1621; a sakamakon haka, rikicin zai ci gaba har tsawon shekaru 27 har zuwa yarjejeniyar zaman lafiya na 1648.