This problem is not Trump’s fault, and he’s right that previous administrations (back to the first President George Bush’s in the late 1980s) have mostly kicked the can down the road. He’s also right that we’re running out of road, now that North Korea has shown the ability to send a missile some 8,000 miles, putting all of the U.S. within its theoretical range.

(We may not be vulnerable yet. North Korea may not be able to attach a nuclear warhead to the missile so that it could survive the heat and friction of re-entering the atmosphere. But if it doesn’t have that capacity yet, it’s making swift progress toward that goal. It’s important to stop North Korea from the final testing needed to be confident of its ability to strike the U.S.)

Some analysts believe in retrospect that it would have made sense for the U.S. to have attacked North Korea’s nuclear sites just as it was beginning its program, in the late 1980s. But even then, North Korea had the capacity to rain chemical and biological weapons on Seoul.

In 1969, President Richard Nixon was tempted to strike at North Korea after it shot down an American spy plane, killing all 31 people aboard. Aides warned that any military strike could escalate into all-out war, and eventually Nixon backed down. Ever since, American presidents have likewise been periodically tempted to strike North Korea after one provocation or another, but have ended up showing restraint for fear of a cataclysmic war.

Hawks say that the continued American restraint has fostered a perception in North Korea that the U.S. is a paper tiger, and frankly there’s something to that. I worry that the U.S. and North Korea are both overconfident. On my recent visit to North Korea, officials repeatedly said that with their bunkers and tunnels, and ability to strike back, they could not only survive a nuclear war with the U.S., but would even prevail.

In Washington, there’s sometimes a similar delusion that a war would be over in a day after the first barrage of American missiles. Remember that tiny Serbia withstood more than two months of NATO bombing in 1999 before agreeing to withdraw from Kosovo; North Korea is incomparably more prepared for enduring and waging war.