Pedzisa mutsara unotevera: Mushure mekurwiswa kwemakemikari muGhouta muna Nyamavhuvhu 2013 panguva yeHondo Yenyika yeSyria, Manchin akati, "Hapana mubvunzo kuti kurwiswa kwakaitika uye hapana mubvunzo kuti kwakagadzirwa pasi pehutongi hwaAssad. Hazvina kujeka kana Assad pachake akapa murayiro wacho. Hazvina kubvumwa". Akapikisa kurwisa kupi nekupi paHurumende yeSyria mukutsiva kwekurwiswa. Panzvimbo pezvo, akaunza chisarudzo chakabatana naSenator Heidi Heitkamp (D-ND) vachikumbira kuti Mutungamiri Obama vauye nehurongwa hwenguva refu pamusoro peSiria uye vashande nediplomatically kuti vave nechokwadi chekuparadzwa kwezvombo zveSiria zvemakemikari. Musi waGunyana 16, 2014, Manchin akazivisa kuti aizovhota achipesana nechisarudzo cheSeneti chinogona kurwisa varwi veSyria vanopikisa. "Pakupedzisira, zvombo zvakawanda zvatinopa vanhu zvinoshandiswa kutirwisa. Vanhu vakawanda vatinodzidzisa vanotishora", akadaro. Akataura nezvezvirongwa zvinodaidzira mauto epasi muSyria, izvo zvakanga zvataurwa nevamwe vaseneti veRepublican, kusanganisira Lindsey Graham weSouth Carolina, se"upenzi", asi akatsigira
2017 Shayrat missile strike yakatangwa nekuraira kweMutungamiri Trump mukupindura kurwiswa kwezvombo zvemakemikari kunonzi kwakaitwa neHurumende yeSyria. Manchin akati "kurwisa kwemanheru kwaikosha kutumira shoko kuhurumende yeSyria nevatsigiri vayo vokuRussia kuti zviito izvi zvinotyisa hazvizoregererwi".