dr. bradley: i would say no. i would say -- you know, the afghan war and the war in iraq does not show the lessons of vietnam at large have been learned. the notion we can intervene in a particular place and engineer a -- either militarily, politically, or socially engineer a transformation place after place after place -- it doesn't work. but all you have to do is look backward in time to think about the british believed they could do that as an imperial power. the french believed they could do that as an imperial power. it did not really work in the end for them as well. the whole notion that these kinds of interventions can achieve the policy goals that are imagined as possible, but that is just fundamentally flawed. yet we seem to do it over and over and over again. when i first started teaching i did believe wow, this could never happen again. people have seen this and learned a set of lessons. and the last 10-15 years would suggest almost the complete other way around. host: history gives us the opportunity

the story from nbc's matt bradley. [ all speak at once ] >> reporter: in a time of polarizing politics -- >> this is a president -- >> firing bob mueller -- >> reporter: -- dr. jordan peterson refuses to be pigeonholed. >> you're not going to decide what words i use. >> reporter: in the past two years, he's been adopted as a hero of the donald trump-loving alt-right. >> diversity, inclusivity, equity, all of those things together, in particular, make up a very toxic brew. >> reporter: he takes direct aim at the far left and says young men have been hurt by a society that overvalues political correctness and pushes them away from traditional male roles. his new book is already a bestseller. hundreds of thousands subscribe to his online speeches -- >> i'm not arguing about you. >> reporter: and his new speaking tour is selling out. >> it feels like a movement and i'm excited to be a part of it. >> i think he's dangerous because of the people he enables. >> reporter: journalist john semley has criticized peterson. >> is there an ideological similarity between jordan peterson and donald trump and his followers? >> i would say fundamentally, yes. they both belie