just a second, but first, let's bring in a senior fellow at the academy of american scientist charles blairyou can see that the international pressure is growing yet we still don't have conclusive evidence this was a chemical attack. we've seen a lot of pictures come out of that site. you've seen them. is an investigation into chemical weapons use warranted at this time, in your opinion? >> certainly, at a minimum, the u.n. team in syria right now should be allowed to conduct the three investigations it was charged to do. the notion that it's going to get into the newest area, i think is unlikely, although the russians have made overtures now, but we don't know how conditional they are. the most important thing to remember about all of this is no matter what they find anywhere and no matter what age sent it is, they will neve be ail to prove who delivered the agent. >> that's true. >> and there are many reasons -- >> i want to say the state department here has said that they do not believe the opposition has the capability of carry out chemical weapons. the opposition claims that medics who

. >> joining us now is charles blair, senior fellow at the federation of american scientists. mr. blair, how would you characterize the u.s. policy towards syria to date? >> it has been very cautious policy at times, not terribly clear in terms of the messages is trying to get out. it has been one that understands that this is a situation where the stakes are incredibly high and there is also a lot of ambiguity. that's the ultimate challenge for any policy maker so it has been a cautious policy but it needs to be. if they get this one wrong it could be absolutely disaste disasterous. >> speaking about ambiguity, doctors without borders are reports many with nerve time gas symptoms. how could the source of the attack be confirmed? >> well, it looks -- the iranians are report ing that the syrians may indeed let the u.n. inspectors in the area. they could go in, take soil, tissue sample, tissue is out of the question but maybe at this point if they have not been all buried they could exhume bd but soil samples will show the products. at this point if they can get people on the ground

i want to bring into the conversation now charles blair. he is a chemical weapons expert. he's a senior fellow at the american federation of scientists. mr. blair, thank you very much for being with us tonight. appreciate your time. >> thank you so much for having me. >> we've been talking in layman's terms about how difficult it is to determine if chemical weapons have been used from afar looking at the evidence we have out of syria, what should we be looking for and how much can you as an expert tell already from what's been made publicly available? >> let me start with your second question first, what should we be looking for in general. it's very difficult from a visual context to ascertain what's going on. in fact, it's impossible to draw any sort of definitive conclusion. some governments have relied entirely on visual confirmation to assert that the syrian regime has used chemical weapons but essentially what you need to do is you need to get people from the u.n., for the prohibition of chemical weapons to go to these sites and conduct highly rigorous scientific inv

. >> charles blair, thank you so much for your insight. we will certainly be calling upon you again. >>> attorneys for staff sergeant robert bale are trying to paint him as a a good father and soldier. the jury deciding whether of par have a list of 20 potential cases and will not call them. we expect staff sergeant bale to be addressing the court, the public, the people of afghanistan in a matter of 15 minutes. we were told to be back in the courtroom at 20 minutes to the hour so we expect to hear from robert bale in what will be unsworn testimony. that means he will developmentst happening. >> we'll let you get back in the courtroom to hear that and get back with you shortly. we'll take a break and come back with more on the other side of the break here on al-jazeera. >>> the justice department going to court today on the texas voter i.d. law. according to attorney general eric holder, the doj will argue the texas law is discriminatory based on race. >>> and the owners of japan's troubled fukushima nuclear plant say they need outside hel

what i meant marandi interim he is a professor at the university of toronto in washington we have charles blair he is the senior fellow on state and non-state threats at the federation of american scientists and also in washington we cross to thomas moore he's a senior fellow and deputy director at the center for strategic and international studies right gentlemen cross-talk rosenberg that means you can jump in anytime you want to run for us that we heard this week a man thomas countryman assistant secretary for international security and nonproliferation says iran's nuclear program possesses the greatest threat to the credibility of the treaty n.p.t. how would you reply to that. i think it would be best to say that the behavior of the united states and the allies is the greatest threat to the treaty because the united states and western powers have been treating iran only not only unfairly but also. in a very disturbing manner the sanctions that have been imposed upon ordinary iranians and their attempts to make ordinary iranians suffer in order for iran to put aside its nuclear program are re