Nightly News | April 25, 2013
>> this, of course, puts the obama administration in a tough spot now. for more on that let's bring in our chief foreign affairs correspondent andrea mitchell . this hardly comes at a time when the u.s. is anxious to get into another conflict.
>> reporter: not at all. officials tell me they know because of a wmd legacy from the iraq debate they need hard evidence chiefly to persuade russia, the remaining ally in the security council , that the assad regime used deadly gas against its own people. secretary kerry talked to his russian counterpart this week in brussels. so far as mick reported the u.s. intelligence only has conclusions based on blood samples and other evidence from two attacks last month. no b absolute proof. they still have to connect the dots. tonight senate intelligence chair dianne feinstein said by going public a desperate assad may think he has nothing to lose by increasing the the use of chemical weapons . this is a signal to assad we have eyes on you. brian?
>> andrea mitchell in our washington bureau. thank you.