use of chemical weapons are abort. >> reporter: putin remains vehemently opposed casting doubt over the evidence that the u.s. government says it has against the syrian regime saying, "if we have objective precise data of who is responsible for these crimes, then we'll react." russia is not alone. >> the nays have it. >> reporter: britain and germany are also refusing to endorse military action. this is the highest tensions have been between the two world powers since the cold war. >> we will have a very bad patch if there is a military attack on syria. and i think wre can expect some pretty frosty time. >> reporter: russia and syria have been strong allies for decad decades. >> russia is very close from syria. buy weapons from each other and kind of a client state. >> reporter: the conflict over syria, just the tip of the iceberg in the riff between the world leaders. obama canceled his private meeting with putin several weeks ago after the russian leader