Frida Ghitis, a former CNN producer and correspondent, is a world affairs columnist. She is a frequent opinion contributor to CNN and The Washington Post and a columnist for World Politics Review. The opinions expressed in this commentary are her own.

(CNN) Something remarkable has just happened in the Trump administration. No, I'm not referring to the latest episodes of the "Trump Show," with the wildly weaving plotline we all recognize. I'm talking about something important and, potentially, very positive. This week, we saw President Donald Trump discover diplomacy. That is, he found out that diplomacy can actually work; that it can yield positive results not just for the country but for him, personally.

Everything is unpredictable in this administration, but we may have reached a key inflection point. The President who disparaged diplomats, who slashed the State Department budget, who mocked his secretary of state, who threatened nuclear war and repeatedly broke the rules of diplomatic protocol, suddenly seemed to gain something closely resembling statesmanlike confidence.

This is not only about the Korean Peninsula, where it's much too early to declare victory despite the historic meeting between the leaders of North and South Korea. We should view that with the skepticism that the lessons of history demand.

But it was striking to see the President tweet this week, with prematurely excited all-caps:"KOREAN WAR TO END!" -- a refreshing shift from his menacing boast that his "Nuclear Button," is much bigger than the North Korean leader's.

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This was also the week that Trump welcomed the President of France with grace and warmth; the week he welcomed German Chancellor Angela Merkel -- whose hand he refused to shake last year -- with a smile and a kiss on each cheek.