Washington: The prospect of a nuclear-armed Iran is the biggest threat facing the world, according to one of Barack Obama's senior foreign policy advisers.
He also signalled that the US Democratic presidential candidate would push Europe to agree on tougher sanctions against Tehran.
In an interview with the Financial Times, Anthony Lake, a former US national security adviser who has worked with Obama since the start of his campaign, also urged the US to keep in mind lessons learnt from its traumatic withdrawal from Vietnam as it assessed the Iraq conflict.
Carrots
"I genuinely believe that the most dangerous crisis we are going to face potentially in the next three to 10 years is if the Iranians get on the edge of developing a nuclear weapon," Lake said.
"If I were the Europeans, I would much rather put on the table more sanctions, together with bigger carrots, and have that negotiation than I would face that crisis down the road."
Obama and his advisers, such as Lake, stress the Democratic candidate's readiness to sit down with Iranian leaders without conditions.
"Unless you assume that [Iranian negotiators] have IQs less than those of eggplants, they are not likely to make major concessions for the privilege of speaking with us. So the question is: what is your strategy for the talks?" Lake said.
"Do you believe that simply sanctioning them can drive them into concessions before you talk, or do you believe that you need to have the sanctions there as a stick at the heart of negotiations," Lake said depicting the Democratic candidate as a tough-minded realist rather than an anti-war politician.
"When I joined the campaign, I remember asking someone at the very beginning: 'Is this a protest campaign or a presidential campaign?'" he said, before insisting that the answer was clearly the latter.
He stressed that Obama, even after withdrawing troops from Iraq over 16 months as he has promised, would maintain "a residual presence for clearly defined missions". These would include military training, and "preparedness to go back in if there are specific acts of genocidal violence".
Responsible strategy
"That is not 'cut and run and let's just see what happens'," Lake said. "It seems to me a very responsible strategy."
Highlighting a parallel with his first posting as assistant to Henry Cabot Lodge, a US ambassador in 1960s Saigon, he said: "It is common sense that we could not leave Vietnam successfully unless we left behind a government in Saigon that could govern successfully. It seems obvious in retrospect; it was not obvious enough to too many politicians at the time. In Iraq it's the same problem."
Lake accused John McCain of "saying we will win by 2013 without defining what winning is" - a reference to a speech in which the Republican candidate predicted that the US would welcome home most of its soldiers from Iraq and Afghanistan by that date.
