Officials told The Daily Beast that President Obama first learned of the alleged plot in June, as undercover agents from the Drug Enforcement Agency were working on a sting against an Iranian American accused in court documents Tuesday of trying to pay Mexican gangsters to murder Ambassador Adel al-Jubeir...The plot, according to an indictment unsealed Tuesday, was approved at the top levels of Iran's elite Quds Force, an organization the United States has accused in the past of aiding the Taliban in Afghanistan and plotting lethal attacks on U.S. soldiers in Iraq. The Quds is an arm of Iran’s elite Revolutionary Guard tasked with carrying out the Islamic regime’s agenda outside the country.

Ken Pollack worries that this attack marks a sea change toward aggressiveness in Iranian foreign policy. Daniel Serwer thinks the right response is ratcheting up international pressure on the nuclear program and calling Ahmadi's "bluff" on negotiations: