SEOUL — Sometimes you have to wonder why Donald Trump spins so many untruths and half-truths and why or whether he thinks he can simply get away with that stuff forever.

That’s why a couple of his boasts last Sunday seemed so unnecessary, so easily questioned, so pointless. The one I liked most was his claim that we would have been at war right now if Barack Obama’s stay in the White House had been extended or if someone like Obama had been elected. That was a jibe against not only Obama but also Hillary Clinton, who would probably have been reasonably firm about North Korea.

At least twice I heard him saying that the Korean standoff had been “a fiery mess” when he took over from Obama — indeed, “We would have been at war with North Korea.” In nearly two and a half years as president, he boasted, “We have had peace.”

It’s very difficult to disprove a hypothetical. One cannot say for sure that we would not have been at war, though I seriously doubt it. It was Trump’s reference to “a fiery mess,” though, that seemed especially noteworthy. Who was it who was threatening “fire and fury” before the U.N. Security Council in 2017 and who was adding to the fury by calling Kim Jong Un “little rocket man”?

In fact, we were far from going to war under Obama. It was in the first year of Trump’s presidency that tensions escalated crazily and war clouds seemed visible on the horizon. That year, 2017, after Trump’s inauguration in January, Kim ordered multiple tests of nuclear warheads and long-range missiles. The U.S. countered by military exercises in which special forces, Navy SEALs and Marines staged mock assassination raids on the North Korean leader in annual war games.

Even so, nobody quite thought war was about to break out in 2017. We are so accustomed to mini-crises and near-crises that it’s hard to convince folks, Korean or foreigner, that we should rush to the bomb shelters or get out of the country on the next plane.

Trump himself that year did his best to fan the flames. I attended one memorable speech that he gave at the National Assembly in Seoul in November 2017 in which he declared, “North Korea is a country ruled as a cult.” At the center: “a deranged belief in the leader’s destiny to rule as parent-protector over a conquered Korean peninsula and an enslaved Korean people.”

Strong stuff — and it got better as Trump warmed to the topic. “The regime has pursued nuclear weapons with the deluded hope that it could blackmail its way to the ultimate objective,” he orated. “That objective we are not going to let it have.”

South Korea, he told Assembly members, “will never allow what’s going on in North Korea to continue to happen.” Why? “The North Korean regime has pursued its nuclear and ballistic missile programs in defiance of every assurance, agreement and commitment it has made to the United States and its allies.”

You have to believe Kim Jong-un must be familiar with every accusation Trump made. Maybe that’s why he decided it was time to try a little reconciliation beginning by sending a team to the Pyeongchang Winter Olympics in February 2018. Simultaneously, he stressed his “byungjin” policy on the need for economic as well as military-nuclear prowess.

Which brings us to the next overstatement — flat-out nonsense — in Trump’s remarks Sunday. That’s the assertion that Obama “wanted to meet, and Chairman Kim would not meet him,” and “the Obama administration was begging for a meeting, they were begging for meetings constantly.”

Initially I wondered if some secret messages had been ricocheting back and forth. I had never heard of such goings-on, but you never know. By now, however, I’ve seen enough denials from the likes of Susan Rice, Obama’s national security adviser, and James Clapper, his director of national intelligence, to be sure there’s nothing whatsoever to this claim.

So why does Trump bother to make up stories? How do such foolish fabrications advance the cause of anything? One answer may be that he’s hiding under a cloud of falsehoods to cover up the danger of falling for the blackmail of which he accused North Korea.

It’s because Kim has so effectively wielded the nuclear club that Trump pleaded with him to agree to more talks between negotiators. Perfect. Now Kim can go on demanding what he’s been demanding all along — an end to sanctions, maybe a “peace treaty,” a year and seven months after Trump vowed, right here in Seoul, “We will not permit America or our allies to be blackmailed or attacked.”