Global implications for the foiled Iranian terror plot

U.S. agents disrupted an Iranian "murder-for-hire" scheme targeting Saudi Arabia's ambassador to the U.S. on Tuesday.  Attorney General Eric Holder said the alleged plan was directed by elements of the Iranian government, but Iranian President Mahmoud Ahmadinejad is saying this "is a fabrication."   Manssor Arbabsiar, a 56-year-old naturalized U.S. citizen, and Gholam Shakuri, an Iran-based member of Iran's Islamic Revolutionary Guard Corps, are accused of a conspiracy to murder a foreign official, conspiracy to use a weapon of mass destruction and conspiracy to commit an act of terrorism, the FBI said Tuesday.

The Saudi ambassador was not the only intended target, U.S. officials said. The suspects also discussed attacking Israeli and Saudi embassies in Washington and possibly Buenos Aires, Argentina, a senior U.S. official said. It is unclear why the Saudi ambassador was targeted, the official said, or how widespread knowledge or approval of the plot was within Iranian President Mahmoud Ahmadinejad's government.

CNN Natl. Security Contributor Fran Townsend assesses the threat level for Americans working oversees – and here at home.