Martha Raddatz interviews Americans who have joined the fight against Russia on the ground in Ukraine on "This Week."<br /><br />SUBSCRIBE to ABC NEWS: https://bit.ly/2vZb6yP<br />Watch More on http://abcnews.go.com/<br />LIKE ABC News on FACEBOOK https://www.facebook.com/abcnews<br />FOLLOW ABC News on TWITTER: https://twitter.com/abc
