Sen. John McCain (R-AZ) said Thursday that President Barack Obama could have prevented Iran's "inept" plot to kill the Saudi ambassador to the United States.

"The thing that's surprising about it is how ridiculously inept [the plot] was," the former Republican presidential nominee told CBS' Eric Hill. "I think the intent is also what we have to worry about."

"When the Iranian demonstrators were in the streets in 2009 and President Obama refused to support them, we could have avoided this. We should have supported them. They could have overthrown the government then."

"Are you saying then that the president's actions or, in your estimation, his inaction at that point in time may have influence this particular plot?" Hill asked.

"No," McCain replied. "I think the president's inaction at the time the demonstrators in Iran in early 2009 when they were chanting in the streets, 'Obama, Obama, are you with us or are you with them?' and he came out and said he didn't want to jeopardize his chances to negotiate with the Iranians was an opportunity that we lost. Because I think if we had supported those demonstrators at the time, it could have meant a significant change in the government of Iran."

Federal officials have said that the alleged plot was foiled after an informant told the DEA that he was approached by an Iranian-American who wanted help from a Mexican drug cartel to assassinate the Saudi ambassador.

Watch this video from CBS' The Early Show, broadcast Oct. 13, 2011.

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