Imposing United Nations sanctions on North Korea is the first major foreign policy success of the Donald Trump administration. The effort has a chance of working — provided Trump keeps following a model borrowed from President Barack Obama’s dealings with Iran. Imitation is the sincerest form of flattery. And the only way to pressure a nuclear or near-nuclear power to the table is with economic sanctions that weaken the regime without threatening its existence.


To get the UN Security Council to act against North Korea, Trump needed both China and Russia to agree, or at least to not veto the sanctions. Equally important, he now needs North Korea’s two major trading partners to implement the restrictions. Those partners happen to be — you guessed it — China and Russia.


It was a deft diplomatic achievement to get the Chinese and the Russians to the first step. Trump’s team was helped by the fact that China doesn’t want the regional or even global destabilization that North Korea is threatening with its nuclear missile expansion. And Russia was not going to stand alone with North Korea once China was on board.


Nevertheless, Trump deserves credit for threatening the possibility of sanctions against Chinese financial institutions that do business with North Korea. That form of disruption would potentially cause trouble for some state-owned Chinese banks, and it was enough leverage to get China to agree to more limited sanctions.


The obvious precedent that Trump’s team followed is Obama’s efforts to isolate Iran through U.S. pressure on European states that did financial business with Iran. Much like China and Russia with regard to North Korea, European countries had relatively little independent reason to sanction Iran, which they did not view a major direct threat to their own interests.


What worked — and what made the sanctions meaningful — was diplomatic pressure convincing the European Union to adopt sanctions. And behind that pressure lay the threat of U.S. sanctions on financial institutions that did business with Iran.


There’s no shame in the Trump administration’s borrowing from the Obama playbook. The question now is whether Trump can follow through to the next stage and craft a deal with North Korea that would serve U.S. interests while allowing other countries to lift their sanctions.


In the case of Iran, the structure of a deal was relatively straightforward even before it was negotiated: Iran would agree to hit the pause button on its efforts become a full-fledged nuclear power, and the U.S. would lift economic sanctions. Critics rightly charged that this didn’t promise a permanent solution and that Iran could potentially restart its program on the clandestine basis without incurring renewed European sanctions. But the Obama administration judged that the halt was better than the alternative — and the Iranians agreed.


North Korea is a little different because it already has nuclear capacity. The realistic scenario here would have to be that, in exchange for sanctions being lifted, North Korea would credibly agree to stop developing long-range missile capacity to deliver its missiles to the West Coast of the U.S. — and perhaps stop adding more warheads.


That deal is conceivable, provided the economic pressure on North Korea is meaningful. The sweet spot for negotiating with a rogue nuclear regime is to impose sanctions that harm the government but don’t threaten its very existence. North Korea’s warheads — which, according to the Washington Post on Tuesday, may have already crossed a major miniaturization threshold — and its missile capacity are sufficient to ensure its survival, much as Iran had reached a critical point in the development of its nuclear capacity.


A nuclear regime won’t ever rationally agree to give up the capacities it has developed to assure that no one can overthrow it.


But a regime intent on nuclear self-preservation can agree to moderate its proliferation program in exchange for the removal of economic sanctions, as the example of Iran shows. So long as North Korea knows it’s safe from regime change, it can seek to stanch the negative effects of sanctions, again presuming they are meaningful.


North Korean willingness to halt the expansion of its nuclear program would put the Trump administration in an awkward position. On the one hand, it would mark the success of its policy. On the other, it would probably require direct negotiations with North Korea and some sort of formal deal to mark the agreement.


Such a deal would put Trump in the difficult position of rather obviously doing for North Korea just what the Obama administration did for Iran. That would be good for the world. Here’s hoping Trump would find a way to resolve the contradiction. I’m sure he can think of something.


Noah Feldman is a Bloomberg View columnist. He is a professor of constitutional and international law at Harvard University and was a clerk to U.S. Supreme Court Justice David Souter. His seven books include “The Three Lives of James Madison: Genius, Partisan, President” and “Cool War: The Future of Global Competition.”