USA TODAY’S FRONT PAGE WENT CRAZY OVER TRUMP’S SPEECH YESTERDAY, but Peggy Noonan sees it differently: Trump Gets Blunt at the United Nations Will bracing clarity make things better or worse? We’ll know soon enough. But he said things the world needed to hear.

It has been charged that Mr. Trump virtually ignored Russia, mentioning it only once, in thanks for supporting sanctions against North Korea. But he also said: “We must reject threats to sovereignty, from the Ukraine to the South China Sea.” That is not ignoring Russia. “We must uphold respect for law, respect for borders, and respect for culture,” he said. “We must work together and confront together those who threaten us with chaos, turmoil, and terror.”

The most publicized section of the speech was on North Korea. He characterized its regime as “depraved,” “twisted,” a “band of criminals.” True enough. North Korea’s “reckless pursuit of nuclear weapons and ballistic missiles” cannot be allowed to continue. In the speech’s most famous flourish: “Rocket Man is on a suicide mission for himself and for his regime.” The U.S. “has great strength and patience, but if it is forced to defend itself or its allies, we will have no choice but to totally destroy North Korea.”

Is this too hot, or helpful, or both? During the Cold War colorful candor produced a great deal. When Ronald Reagan was drop-dead blunt about the nature of the Soviet Union, foreign affairs was a high-stakes chess game between two superpowers. The context now is a less clearly demarcated world in which anyone with a weapon of mass destruction is, for the moment, a “superpower.” It’s hard to know if blunt talk will excite nuts into greater activity, or if bracing clarity about the risks they’re taking will slow them down, make them question their ambitions and intentions.

But the U.N. needed to hear clearly and unequivocally the gravity with which the American president views North Korea. Ultimately, as Mr. Trump noted, confronting this question is “what the United Nations is for.”

A great line—because it spoke a great truth—was this: “The problem in Venezuela is not that socialism has been poorly implemented, but that socialism has been faithfully implemented.” Mr. Trump then paused and looked at the audience. It struck some as a “please clap” moment. It struck me as a stare-down: I’m saying something a lot of you need to hear. You’re not going to like it, and I’m going to watch you not like it.

Two final points: One is that Mr. Trump is on a roll, a sustained one the past few weeks, and this is new. All levels of government performed well in the hurricanes. Mr. Trump showed competence, focus and warmth. His bipartisan outreach, however it ends, went over well with core supporters and others. He had a strong speech at the U.N., in fact a successful U.N. week, beginning to end. His poll numbers are inching toward 40%.

Which gets us to point two: This is a very important moment for him. History suggests he will ruin it any minute with intemperate statements, wiggy decisions or crazy tweets.

Is that what history suggests?