operated, financed and directed by the force. reporter: a senior official says the official from the irgcrr is a hands-on leader who has the ear of the supreme leader. asked if it backed up a link to the ayatollah. it would be highly unlikely that an evented of this magnitude would not have senior leadership involvement. reporter. on cap till hill, lawmakers debated on more sanctions to pressure iran. we have a certain level of sanctions that obviously they can live with because they have been living with it. the goal is not to pat ourselves on the back and issue press releases here. it is to inflict crippling economic pain there. reporter: one dramatic cable by wikileaks says that they wanted to take out the nuclear program. the u.s. envoy was the target of the assassination plot t. may partially explain why senior i iranian officials apparently
with my national security team and republican and democratic leaders of congress. in the coming hours and days, my administration will keep the american people fully informed. make no mistake, today we are part of a broad coalition. we are answering the calls of a threatened people, and we are acting in the interests of the united states and the world. thank you very much. president barack obama there from brasilia, brazil, in his three-nation tour underscoring the u.s. will be playing a limited role in this operation already under way, escalating in libya. and underlining the fact that the u.s. will not, and he said, repeat, not deploy ground troops in libya. ed henry is traveling with the president and joins us from brasilia. what have you learned from your sources about how long america s leadership involvement will be