1,400 of them are deployable. submarine launch missiles and also on bombers. would russia's president really use them? britain defense secretary said he thinks putin is bluffing. >> he reminded everyone he has nuclear weapons. people get worried. secondly distracted from what's going wrong in ukraine. >> the mere threat itself is designed to change the dynamic of the war. >> he's in a corner. somebody in a corner in that situation becomes more dangerous. more prepared to take risk. still it's most unlikely. i don't want to alarm people. the chance of this happening is long but not zero.