Canadians expect their government officials to endeavour to make decisions "for the wider interests of humanity," Harper told a reception at the glitzy Waldorf Astoria hotel after receiving his award from the Appeal of Conscience Foundation.
"That is, of course, not the same thing as trying to court every dictator with a vote at the United Nations, or just going along with every international consensus, no matter how self-evidently wrong-headed."
Harper's shot at the UN came as he was criticized back home for once again skipping the United Nations General Assembly.
Hundreds of world leaders were gathered just a few blocks away discussing the biggest global issues of the day, including the situation in Syria, the ominous dispute between Israel and Iran and the eruption of anti-American violence in the Middle East.
The prime minister pulled no punches in his own remarks about Iran after he accepted the foundation's "world statesman" award from storied U.S. statesman Henry Kissinger, Richard Nixon's onetime secretary of state.
The civilized world must not "shrink from recognizing evil in the world for what it is. Our government simply contends that the international community must do more to further pressure and isolate this regime," Harper said to applause.
The elderly Kissinger, now 89 and frail, met with Harper earlier in the day at his Park Avenue office and said later Thursday that he agreed with Harper's tough stand against Iran.
Canada recently closed its embassy in Tehran and Iran returned fire this week, issuing a travel advisory to its citizens to steer clear of Canada because it was rife with "Iranophobia."
"Unless Iran feels isolated and without support, it won't take the steps that it needs to take," Kissinger told reporters before Harper took to the stage.
Some of the world's emerging powers "are neither sure friends nor implacable foes," Harper told the Waldorf Astoria reception attended by several VIPs, including Gary Doer, Canada's U.S. ambassador, David Jacobson, the U.S. envoy to Canada and even NHL commissioner Gary Bettman.
Other countries, however, "constitute unambiguously a clear and present danger and thus demand a very sober assessment," he said, pointing the finger once again at Iran.
"I speak not merely of its appalling record of human rights abuse or its active assistance to the brutal regime in Syria or its undeniable support of terrorist entities or its determined pursuit of nuclear weapons," he said.
"Rather it is the combination of all these things with a truly malevolent ideology."
Harper received a standing ovation when he told the packed ballroom that the world must speak out against the Iranian regime and "speak in support of the country that its hatred most immediately threatens — the state of Israel."
Rabbi Arthur Schneier, the founder of the Appeal of Conscience Foundation, praised Harper in a welcoming ceremony before the dinner.
"Not only do you care about your people of Canada, but you care about all humanity, around the world. So keep this as a token of our respect," he said as he handed the prime minister the foundation's trophy.
Harper responded: "It's a great honour for me, and especially for our country."
Past winners of the award include Canada's Jean Chretien, Nicolas Sarkozy of France and former British prime minister Gordon Brown.
As both Israeli Prime Minister Benjamin Netanyahu and Mahmoud Abbas, head of the Palestinian Authority, addressed the United Nations on Thursday, Harper met with the Haitian president at another nearby hotel.
Harper and Michel Martelly discussed efforts to bring economic stability to the impoverished, long-suffering Caribbean island, the recipient of $1 billion in Canadian aid since 2006.
The prime minister also sat down later in the day at the UN with Abbas, and was scheduled to meet on Friday morning with Netanyahu. The Middle East peace process was the focus of the Harper/Abbas discussions.
In the Israeli prime minister's address to the UN on Thursday, he cautioned that Iran is amassing enough enriched uranium to soon build a nuclear bomb, urging fellow world leaders to draw a "red line" to shut the Iranians down.
"I believe that faced with a clear red line, Iran will back down — and it will give more time for sanctions and diplomacy," Netanyahu said.
"Red lines don't lead to war, red lines prevent war ... nothing could imperil the world more than a nuclear-armed Iran."
Harper is onside with Netanyahu's approach, and has long been avidly pro-Israel.
"In supporting Israel, we don't sanction every policy its government pursues," Harper said Thursday.
"When, however, it is the one country of the global community whose very existence is threatened, our government does refuse to use international fora to single out Israel for criticism."
Whatever Israel's shortcomings, he added, "neither its existence nor its policies are responsible for the pathologies present in that part of the world. We are also mindful of the lesson of history: that those who single out the Jewish people as a target of racial and religious bigotry will inevitably be a threat to all of us."
Harper has faced a barrage of criticism in Canada for his decision to opt out of speaking to the UN again this year.
But he's insisted that it's not standard procedure for the Canadian prime minister to address the General Assembly every year. The UN has met seven times since he was elected; Harper's spoken twice, in 2006 and in 2010.
In his place, Foreign Affairs Minister John Baird will address the UN on Monday.