New Mexico Gov. Bill Richardson, a candidate for the Democratic presidential nomination, called for talks with Iran without preconditions.”Refusing to engage Iran diplomatically prevented us from making headway on issues vital to our national security, including not only nuclear weapons but also Iraq, energy security and Middle East peace,” Richardson said in a speech Wednesday night at the Center for National Policy in Washington. “We need to approach Iran with both fierce determination and with open eyes.”The key is to make them see that they will be better off and more secure without nukes than with them. If we unite the world behind the right carrots and sticks, and provide the Iranians with face-saving ways to step back from the nuclear brink, we will prevail.”Richardson said the United States would make it clear in such a dialogue that incentives such as an end to economic sanctions would be conditioned on an end to Holocaust denial and threats against Israel. He also said threats of attack against Iran are counterproductive.”If we want Iran to improve its behavior, we would do well to stop threatening to attack them,” said Richardson, who has successfully negotiated backdowns from crises in North Korea and Sudan, among other regions.