Ironically, given how Trump has handled the two cases, the sympathy of our allies and the broader international community lies with Iran and North Korea. He has alienated U.S. allies just when he needs them most, to the benefit of geopolitical rivals: Much to Russia's delight, the demise of the Iran deal has created a rift between the U.S. and its European allies, while the collapse of the Trump–Kim summit has put the U.S. at odds with South Korea, which suits China.

The administration’s strategy can be boiled down to the hope that “maximum pressure” will compel Iran and North Korea to accept new deals. But why would they? The threat of maximum pressure rings hollow when there is scant support for it among U.S. allies. Nor is it convincing that the U.S. would be able to effectively apply maximum pressure on both Iran and North Korea at the same time.

The bottom line: The global expectation now is that Washington will fail. That does not bode well for U.S. foreign policy.

Vali Nasr is dean of the Johns Hopkins School of Advanced International Studies.

First, North Korea already has nuclear weapons, which Kim Jong-un considers sufficient leverage to negotiate effectively with U.S. By killing the Iran deal, Trump will only convince Tehran that it should secure similar leverage — a bigger nuclear program, perhaps even nuclear weapons — before resuming talks. Trump may also find it difficult to squeeze Iran while continuing to squeeze North Korea, potentially giving Iran even more time to work with. After all, to keep North Korea talking and ultimately making concessions will require concerted and ongoing U.S. pressure.

Second, Iran has a true domestic politics with many competing factions, despite its authoritarian edifice. Although an absolute dictator may be swayed, Iran’s leaders, jostling for power and position, won’t bow to brazen intimidation any more than American politicians would. In fact, Trump’s tactics will likely embolden hardliners in Tehran, who will see an opportunity to sideline rivals tainted by an association with the U.S. — in which case everything that worries the U.S. about Iran will only get worse.

Why it matters: It’s a mistake for Trump to follow his North Korea model — which is still being tested — in deciding the fate of the Iran nuclear deal. A victory for hardliners in Iran will only put the U.S. in a more difficult negotiating position down the line, with much higher stakes.

Vali Nasr is dean of the Johns Hopkins School of Advanced International Studies.