▁S inking ▁of ▁HMS ▁York ), ▁ ▁man ned ▁tor ped o es ▁( the ▁Ra id ▁on ▁Alexand ria ) ▁and ▁G amma ▁f rog men ▁( ag ain st ▁Gib ral tar ). ▁During ▁the ▁campaign ▁Dec ima ▁M AS ▁took ▁part ▁in ▁more ▁than ▁a ▁dozen ▁operations ▁which ▁s ank ▁or ▁dam aged ▁five ▁war ships ▁( tot alling ▁ 7 2 , 0 0 0 ▁G ross ▁Register ▁T onn age ) ▁and ▁ 2 0 ▁merchant ▁ships ▁( tot alling ▁ 1 3 0 , 0 0 0 ▁G RT ). ▁ ▁In ▁ 1 9 4 3 , ▁after ▁the ▁Italian ▁dict ator ▁Ben ito ▁M uss ol ini ▁was ▁ou sted , ▁Italy ▁left ▁the ▁Tri part ite ▁P act . ▁ ▁Some ▁of ▁the ▁X ª ▁M AS ▁men ▁who ▁were ▁station ed ▁in ▁German - occup ied ▁northern ▁Italy ▁en list ed ▁to ▁fight ▁for ▁M uss ol ini ' s ▁newly ▁formed ▁Italian ▁Social ▁Republic ▁( Rep ub blica ▁Soc iale ▁Italiana ▁or ▁R SI ) ▁and ▁retained ▁the ▁unit ▁title , ▁but ▁were ▁primarily ▁employed ▁as ▁an ▁anti - part isan ▁force ▁operating ▁on ▁land . ▁Other ▁X ª ▁M AS ▁men ▁in ▁southern ▁Italy ▁or ▁other ▁Al lied - occup ied ▁areas ▁joined ▁the ▁Italian ▁Co - B ell iger ent ▁Navy ▁as ▁part ▁of ▁the ▁Mari ass al to ▁( N aval ▁Ass ault ) ▁unit . ▁ ▁Historical ▁background ▁In ▁World ▁War ▁I , ▁on ▁November ▁ 1 ,