Are there no Edward Tellers left among nuclear policy wonks? As world diplomats gathered in Turtle Bay this week to review the Nuclear Non-Proliferation Treaty, I was thinking about two men whom I met in the early 1980s and who represent the opposite ends of American thinking on all things atomic: Father George Zabelka and Edward Teller.

At the United Nations, President Obama’s America is claiming leadership in the race toward a nuclear-free world. Along with our newest partner — Russia — we’re working on agreements that would create nuclear-free zones around the world, especially in the Middle East. This was Zabelka’s dream, borne out of guilt he had developed over his involvement in the nuclear bombing of Japan.

As all are shuddering at the thought of nuclear Iran, no one in Washington, let alone here at the United Nations, any longer advocates the show of force that guided Mr. Teller, the scientist who had inspired President Reagan (and also title character of in the movie Dr. Strangelove).

Teller’s doctrine would lead to a different path: Rather than getting Iran to agree to disarm because, see, we are complying with all our NPT obligations, let’s threaten the mullahs with using our own nuclear weapons to stop them from getting theirs.

But let’s go back to the philosophies of these two men.

Thirty years ago I spent a day of vigorous walking with the already aging Zabelka, who died a decade later, in 1992. He was marching along with a group of young Catholic friends across the “green line” that had once separated Israel and Jordan. That day trip was but one leg in a yearlong pilgrimage to rid the world of nuclear weapons. They had started at Washington State and were scheduled, by Christmas, to get to the city where Jesus was born, Bethlehem.

The group was of the idealistic, clueless variety — glossy eyed young men and women speaking endlessly about how great a world without nukes could be. Zabelka, however, was much more interesting, even though he spewed the same anti-nukes rhetoric as the rest: America and Israel should get rid of their atomic wares, he told me, because such weapons were immoral.

What was interesting,  however, was how Zabelka had arrived at that position. As he had acknowledged, he was a man with a cross to bear. In his youth he had served as the Catholic Chaplain of the Tinian Island-based 509th Composite Group — the United States Army air force team that ended the war by dropping the atomic bombs.

Zabelka told me that in 1945 he had no clue that the “gimmick bomb,” as the secretive new weapon was known on the island, would end up ushering-in the nuclear age. “We didn’t know,” he said over and over again, raising his voice as if trying mostly to convince himself. “You just don’t understand: none of us knew what it was.”

Earlier in the war, airmen like the devoutly Catholic George Sweeney, would come to confession, telling Zabelka of their moral suffering: they were able to see from their cockpits the pleading eyes of Japanese children, just before dropping a bomb on their village. Zabelka, the patriotic priest, would tell Sweeney and the other pilots that they were doing the right thing by God. Winning America’s war was paramount. Sweeney was the pilot who was then picked to pilot the Bockscar, the plane that dropped the bomb on Nagasaki.

Later, realizing the historical role he had played in providing moral comfort for the men who dropped the Big One, Zabelka’s life had changed. He eventually became a devout pacifist, organizing non-violent marches throughout the world to end the presence of nuclear weapons anywhere.

When I met Edward Teller at a Tel Aviv hotel lobby in the 1980s, the man with the famed bushy eyebrows was unapologetic about America’s nuclear powers. Teller, who died in 2003, spoke with me for a few hours, mostly about the moral difference between free societies and the totalitarian regimes that ruled Soviet satellites like Hungary, the country of his birth, and why America should prevail over them.

Nicknamed “the father of the hydrogen bomb,” Teller was one of the only scientists of the Manhattan Project who remained an atomic hawk his whole life. He kept promoting one nuclear project after another. He inspired Reagan’s missile defense vision, which was derided at the time as “Star Wars” but which, as President Gorbachev later acknowledged, was probably the last nail in the Soviet coffin.

Treaties like the NPT had  little use for Teller. He became friend with a Tel Aviv-based scientist, Yuval Neeman, who was ridiculed by the left as Israel’s Dr. Strangelove. In the 1960s, Teller reportedly helped Israel to advance its nuclear capabilities, as well as its “nuclear ambiguity” policy. He advised his fellow Jews to never sign the NPT or any other treaty they had no plan to abide by.

Now that President Obama declares that the NPT is the “cornerstone” of America’s nuclear policy, we’re left with a dilemma that Zabelka never considered, but which had kept Teller awake at night: treaties are only as good as the countries adhering to them.

The NPT calls on the “haves” – the five established nuclear powers – to gradually reduce their stockpiles. Mr. Obama eagerly shows how America and Russia are doing just that. It also calls on the have-nots to refrain from obtaining weapons, and law-abiding countries will indeed do their part. But the cheaters, countries like Iraq, Syria and now Iran, secretly developed nuclear programs. Iran and others now contemplate North Korea’s trail-blazing example: leaving the NPT once they had obtained the bomb.

Without the Teller-advocated deterrence, more cheaters will get nuclear bombs even as the Zabelkas march to rid the world of an immoral and awful instrument of war.