>> reporter: vladimir putin responded to his horror in traditional fashion, by hunkering down, deflecting blame toward ukraine. >> translator: this tragedy would not have happened if there had been peace on that land or if military operations in southeastern ukraine had not been renewed. >> reporter: but u.s. leaders are blunt, while he didn't set the launch codes, putin's support for pro-russian rebels in ukraine. >> he has the most control over that situation. and so far at least he has not exercised it. >> i think he is responsible. >> reporter: analysts say in the immediate aftermath of the malaysia airlines crash, vladimir putin is under enormous pressure. >> this is one of the most difficult situations that vladimir putin has faced since he first became president back in 2000. >> reporter: of his most powerful partners, germany is pressuring him to pull back support of the pro-russian rebels and china is not saying anything one way or another.