Presumptive Republican nominee Sen. John McCain used his time at the podium at the American Israel Public Affairs Committee on Monday to launch a withering attack on Democratic rival Barack Obama's Iran policy. A presidential summit with Iranian leaders, which McCain implied that Obama supports, would produce an "earful of anti-Semitic rants" from the Holocaust-denying Iranian President Mahmoud Ahmadinejad, as well as harm to Iranian dissidents and the strengthening of hardliners. Click below to watch address: McCain, who called for tough sanctions against Iran, earned his most enthusiastic ovation for another statement referencing the Holocaust: "When we join in saying 'never again,' this is not a wish, a request, or a plea to the enemies of Israel. It is a promise that the United States and Israel will honor, against any enemy who cares to test us." He also received rousing applause for his lambasting of the idea of that the US isn't dealing effectively with Iran because it isn't meeting with its leaders. "The idea that they now seek nuclear weapons because we refuse to engage in presidential-level talks is a serious misreading of history," McCain said to rousing applause. "We hear talk of a meeting with the Iranian leadership offered up as if it were some sudden inspiration, a bold new idea that somehow nobody has ever though of before," he said, recalling several overtures recent US leaders had made to Iran with little to show for it. Obama will address the AIPAC Policy Conference on Wednesday morning, when he hopes that Tuesday's final Democratic primaries, in South Dakota and Montana, will have given him a definitive edge in securing the party nomination over Hillary Clinton, who is also scheduled to speak to AIPAC then. In the past, Obama has expressed a willingness to meet with Iran's leaders without preconditions in an effort to use diplomacy to stop Iran from acquiring nuclear weapons, a position McCain has used to try to portray his competitor as naive and inexperienced. But the Obama campaign quickly pushed back against the attack, arguing that McCain has inflexibly pursued policies that endanger America and Israel. "John McCain stubbornly insists on continuing a dangerous and failed foreign policy that has clearly made the United States and Israel less secure," Obama spokesman Hari Sevugan said. "He promises sanctions that the Bush administration has been unable to persuade the (United Nations) Security Council to deliver." In his AIPAC speech, McCain called for tough sanctions, outside the UN if necessary, particularly against the Central Bank of Iran, and restrict Iran's import of refined petroleum products. McCain also criticized Obama by name for his support of troop withdrawals from Iraq, arguing that would jeopardize Israel's security and lead to civil war and genocide. To applause, McCain declared, "We must not let this happen." Sevugan countered that McCain "promises to continue a war in Iraq that has emboldened Iran and strengthened its hand." MK Ephraim Sneh warned the AIPAC audience that a year from now, Iran would be on the verge of completing a nuclear weapon - and that Israel was preparing to face that challenge alone. "There will be a government in Israel which will not allow it to happen," he declared, and added, "Our assumption is that we may face the problem alone." Sneh continued, "if we are alone, we will have to act alone." He did not specify what action Israel was contemplating, though there has been speculation as to whether Israel is planning a military attack. Iraq was the focus on some controversy at last year's AIPAC conference, when some members of the audience booed Nancy Pelosi, the speaker of the US House of Representatives, when she spoke about the problems created by the war in Iraq. This year, before McCain took the podium to open the three-day conference, Bernice Manocherian, the immediate past president of AIPAC, urged members of the audience to be on their best behavior. Addressing the more than 7,000 conference participants, including 1,200 students from 363 colleges, she told them, "We will treat all of the speakers with respect and dignity, remembering that they are all our friends." Prime Minister Ehud Olmert will be speaking at the conference, and could come under criticism for his efforts to engage the Palestinians and Syrians. Opposition leader Binyamin Netanyahu (Likud), who was in town to attend the conference, spoke to both Democratic contenders. When Obama informed Netanyahu that he was considering visiting Israel this summer, Netanyahu told him he should visit Sderot. The Associated Press contributed to this report.