arsenal including a torpedo that could allegedly reach the west coast. barbara starr fills us in. >> reporter: while president trump navigates the political minefield of the russia investigation -- >> there's been no collusion. there's been no crime. >> reporter: pentagon and state department unveiled the toughest line yet against vladimir putin's military in a report on nuclear threats and the trump administration solutions. >> russia has increased its reliance on nuclear weapons and its capabilities. and as we've pointed out, it's building a large and diverse nuclear arsenal. >> reporter: the pentagon detailing 2,000 russian nuclear capable weapons that could hit europe including missiles, bombs, torpedos. for the first time confirming russia is developing an underwater drone that can potentially travel thousands of miles and strike the u.s.