Trump's decision not to re-certify the Iran deal "sends an unmistakable signal to North Korea," Senator Tim Kaine said this week, which is that the "U.S. will back out of a nuclear deal even when it's being complied with." This, he says, drives "the chances of a diplomatic resolution in North Korea down to zero."
Why it matters: The potential for productive talks between the U.S. and North Korea is tenuous, even as tensions and militaristic threats ramp up.
Donald Trump is now well-recognized as the president who hasn't been bound by the same niceties as his predecessors — whether on Twitter or in public remarks. He sparked controversy again this week, when he impugned past presidents for not calling families of service members killed in combat — the latest incident where his inclination to speak off the cuff went beyond the normal remarks of prior presidents.
Bottom line: It was assumed that after taking office Trump's rhetoric would become more mild, but he's proven that he will continue to say what he wants. As Axios wrote in March, Trump is Trump, "the one guy who's NOT CHANGING is a 70-year-old billionaire with his name on the building."