There are few sensations in life so wonderful as that special knowledge that you are not afraid, when so many others are. It’s a powerful political emotion. There are your countrymen, cowering from the threats of a nuclear Iran and Al Qaeda. Here you are, unwilling to be manipulated. They’re with Bush and Hillary and their politics of fear. You’re with Senator Obama and his politics of hope.

His opposition to the “politics of fear” is one of the Illinois junior senator’s main selling points in the primary season. In the South Carolina debates, Mr. Obama said Democrats had to counter the warmonger McCain by standing up and saying, “We’ve got to overcome the politics of fear in this country.” The week before, he accused Hillary Clinton of frightening Democrats by raising the specter of terrorists launching an attack to test an unseasoned president.

As it happens, Mrs. Clinton was referring to the attacks launched in the opening days of Prime Minister Brown’s government and thwarted this summer at Glasgow and London. But never mind, Mrs. Clinton was trying to scare voters, and that’s just something Mr. Obama won’t do.

The phrase, “politics of fear,” reemerged from the dustbin of anti-anti-communism on far left Web sites like Alternet in late 2002. In the Cold War, it was employed to deride public school air raid drills, the House’s un-American Activities Committee, and Ronald Reagan’s anti-red campaigns. Since the end of the Cold War, the phrase has been resurrected by politicians and pundits alike to say the electorate ought to fear the people trying to scare us, not these terrorists and tyrants they keep going on about.

In 2004, the British state broadcasting arm, the BBC, aired a three-part documentary called the “Power of Nightmares: The Rise of the Politics of Fear.” According to this film, the threat of Al Qaeda and radical Islam was a foil for a broader neoconservative power grab. The two radical movements are equivalent, relying on one another to scare the good and decent majorities of Europe and America.

Mr. Obama would never say anything this strident. Part of his appeal is that at his best he transcends partisanship. But the “politics of fear” signals the left’s own scary narrative about the Bush years, namely that our government was taken over by neoconservatives briefly to launch the Iraq war.

This is the chord Mr. Obama strikes when he boasts of his opposition to a non-binding resolution supporting efforts already underway to counter Iran’s proxies in Iraq. Mr. Obama has attacked Mrs. Clinton for voting for the Iran resolution sponsored by Senators Kyl and Lieberman, implying that the legislation would give Mr. Bush the authority to invade Persia. His Web site says Mr. Obama “believes that it was reckless for Congress to give George Bush any justification to extend the Iraq War or to attack Iran. Obama also introduced a resolution in the Senate declaring that no act of Congress — including Kyl-Lieberman — gives the Bush administration authorization to attack Iran.”

Neither Messrs. Kyl nor Lieberman ever said it did. It expressed a sense of the Senate, whereas the 2002 resolution against Saddam Hussein gave explicit authorization to use force. What’s more, the course recommended by the non-binding resolution was a response to reams of reporting from Iraq that the Iranian revolutionary guard supported terrorists trying to dissolve Iraq and kill American soldiers, a point Mr. Obama conceded as recently as a year ago.

Today it is different for the senator. He and his supporters believe peaceful coexistence with Iran only requires the courage to meet with Iran’s leaders. The senator likes to quote President Kennedy’s aphorism that we should not negotiate out of fear, or fear to negotiate. But Mr. Obama presumes that Iran would be willing to negotiate and that the only thing holding them back is the lack of diplomatic courage on the part of the American administration.

Contrary to Mr. Obama’s anti-fear mongering, the Iranians have had a standing offer from Mr. Bush since 2006: Stop enriching uranium and Secretary of State Rice will start talking to you. Were the Mullahs interested in negotiations, they would suspend an enrichment program they always have the option to restart.

It’s illuminating that these details are of so little concern to Mr. Obama. Never mind that every administration since Jimmy Carter has sought a détente with Tehran’s Mullahs. Forget for a moment that Mr. Bush has not yet bombed Iran’s enrichment facilities — despite the dire warnings of the left that he would — and instead sought to dissuade the Mullahs from their nuclear activities through diplomatic sanction and censure.

Mr. Obama seeks advantage in the war against fear. Mr. Bush, Mrs. Clinton, the Republicans, official Washington, and the neoconservatives are trying to scare you. If the voters fall for it again, the republic will be thrown into yet another unnecessary and disastrous war, a prospect that Mr. Obama reckons should terrify all of us. Not that the senator’s trying to scare anyone.

elake@nysun.com