. >> reporter: experts say while the new tactics, training and weapons have been inagainstable to isis on the battlefield and a crucial reason why they've captured so much more territory since june. there's another weapon they use, a psychological one that's also been very effective. a warning, you're about to see some disturbing video. isis units often win before they get to the battlefield because of this. horrific propaganda videos show isis militants capturing opponents shooting them in ditches. displays the severed heads of enemies in poles. >> when it comes to ice its, it's not what they're capable of but what people tear they're capable of which gives them this advantage. they've had a deliberate stand of terrorizing military. >> reporter: experts say those who see the videos often quit and run before the battle starts. brian todd, cnn, washington. >>> and much more to come here on cnn. hostilities are renewed between israel and hamas. >> both sides blame each other. cnn is live in jerusalem and gaza with your up tot minute reporting. >>> plus, an international health emergency.

not only ukraine declared independence, but every other republic declared inagainst at that time -- independence at that time, and the united states didn't want that to happen. after that, yeltsin changes the course. but this particular -- these particular regions were already there from the very beginning. another point linking events of 1991 and today's event that i want to make was about the question of what drives putin's policy in the area today, whether this is really the way how the united states and the nato countries are moving into the neighborhood, or there is, there is something else. and my take on that is that it should be something else. very often what is mentioned as the reason for unhappiness is the -- [inaudible] given to -- [inaudible] after the reunification of germany. history is a funny thing, you can go into history and find almost everything what you want to find there. first of all, except the document that everyone -- [inaudible] written. you go to september of 1991, and you can see yeltsin and secretary of state james baker discussing the issue of possible russian mem