Juan Cole, one of the most consistently astute observers of the struggle in the Middle East, explains that DAESH depends on fear to drive recruits to its hideous mission. The way to choke off that recruiting tool and speed the defeat of DAESH is with a warm welcome to Muslims and Muslim refugees:
Counter-terrorism therefore in this case would involve counteracting Daesh polarization and spread of hatred. The only way to impede their attempt at radicalizing Muslims is to reach out to Muslims with love.
Conversely the expressions of fear and hate from people like Donald Trump actually make the war harder to win by driving Muslims into the arms of DAESH. Here is a link to Juan Cole’s post.