dr. jerry avorn.nk you. >> ifill: in ukraine, protesters are back at the barricades again, their anger refueled by their president's new dealings with moscow. chief foreign affairs correspondent margaret warner reports. >> warner: russian president vladimir putin threw embattled ukrainian president viktor yanukovich a lifeline today, agreeing to buy $15 billion in ukrainian bonds and to slash the selling price of russian natural gas by about a third. he launched their talks at the kremlin by voicing solidarity with his economically strapped neighbor. >> ( translated ): i very much hope that we will be able to move forward in solving the most sensitive issues for us. without any doubt, ukraine is our strategic partner and ally in every sense of this word. >> warner: but putin insisted there was no discussion of ukraine becoming part of an economic trading bloc of former soviet states, over which yanukovich has been criticized at home. >> ( translated ): i would like to calm everybody down. we have not