Bureaucracies create the "facts" about any particular issue that support their interests. Defining the Iranian nuclear threat as a threat to proliferate was clearly in the interests of the counter-proliferation offices in the White House, State Department, and CIA, which wielded strong influence over the issue within their respective institutions.
The senior officials on Obama's transition team and his initial national security team, moreover, had been closely associated with different versions of the policy of treating Iran as nuclear rogue state in previous administrations.
As Secretary of Defense in the Bush administration, Robert Gates had catered to the interests of the Congressional-military-industrial alliance behind a missile defense program in the United States, which had required an alarmist definition of threat from Iran's missile and nuclear programs.
Tom Donilon and Wendy Sherman, who had presided over Obama's State Department transition, were both proteges of the Clinton administration's Secretary of State Warren Christopher, who was an ardent proponent of demonizing Iran. It should be of no surprise that Donilon said in 2011 that Iran had "a record of deceit and deception," and that Sherman declared in Congressional testimony in 2013 that Iran couldn't be trusted because "We know that deception is part of the DNA."
Secretary Kerry and other Obama administration officials may have moderated their views of the Iran's nuclear program over the course of negotiations, but the external and domestic pressures for an even tougher line toward Iran have clearly outweighed any such learning process on the issue.
If it isn't changed dramatically from Kerry's testimony, the administration's choice of political strategy will certainly contribute to a domestic political atmosphere in which even the most limited steps toward greater cooperation with Iran are all but impossible for years to come.
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