I’ve never found this argument convincing, mainly because it’s been used to advocate extra-military, Hearts and Minds type nation-building exercises (worst example of this thinking being the ever-daffy Marie Harf’s suggestion that the answer for ISIS is ‘jobs’).
As much as I dislike some of the implications of drawing parallels between terrorism and crime, I do think they’re comparable in one sense. No one presumes that we’ll ever be without theft or assault or vandalism so therefore we should stop prosecuting the individual offenders — we understand that they’ll always be part of our society and just accept that we’ll always have to fight to suppress it and keep it on the margins of society.
I think we’ve reached the same point with Islamic terrorism — it will always be with us, but we need to suppress it (military action overseas) and keep it on the margins of society (immigration restrictions).