For years, the North’s medium-range missiles have been able to reach South Korea and Japan with ease, and American intelligence officials believe the missiles are capable of carrying nuclear warheads.
But this latest test suggests that the United States may already be in range as well, and that, as one former top American intelligence official noted recently, would put enormous pressure on American missile defenses that few trust to work.
On Tuesday, Mr. Trump’s secretary of state, Rex W. Tillerson, called for “global action” and for the United Nations Security Council to “enact stronger measures” against the North’s government in Pyongyang. He added that the United States would consider nations that provide economic or military help to to be “aiding and abetting a dangerous regime.”
Mr. Trump still has some time to act. What the North Koreans accomplished while Americans focused on Independence Day celebrations was a breakthrough, but not a vivid demonstration of their nuclear reach.
Their missile traveled only about 580 miles, by itself no great achievement. But it got there by taking a 1,700-mile trip into space and re-entering the atmosphere, a flight that lasted 37 minutes by the calculation of the United States Pacific Command (and a few minutes longer according to the North Koreans).
Flatten that out, and you have a missile that could reach Alaska, but not Los Angeles. That bolsters the assessment of the director of the Missile Defense Agency, Vice Adm. James D. Syring, who said at a congressional hearing last month that the United States “must assume that North Korea can reach us with a ballistic missile.”
Perhaps that is why Mr. Trump has not issued any “red lines” that the North Koreans cannot step over.
He has not even repeated the policy that President George W. Bush laid out in October 2006 after the North’s first nuclear test: that he would hold the country “” if it shared its nuclear technology with any other nation or terrorist group. Mr. Trump’s advisers say they see little merit in drawing lines that could limit options, and they would rather keep the North guessing.
So what are Mr. Trump’s options, and what are their downsides?
There is classic containment: limiting an adversary’s ability to expand its influence, as the United States did against a much more powerful foe, the Soviet Union. But that does not solve the problem; it is just a way of living with it.
He could step up sanctions, bolster the American naval presence off the Korean Peninsula — “we’re sending an armada,” he boasted in April — and accelerate the secret American cyberprogram to sabotage missile launches. But if that combination of intimidation and technical wizardry had been a success, Mr. Kim would not have conducted the test on Tuesday, knowing that it would lead only to more sanctions, more military pressure and more covert activity — and perhaps persuade China that it has no choice but to intervene more decisively.
So far, Mr. Trump’s early enthusiasm that he had cajoled China’s president, Xi Jinping, to crack down on the North has resulted in predictable disappointment. Recently, that the United States was prepared to go it alone in confronting North Korea, but the Chinese may consider that an empty threat.
He could also take another step and threaten pre-emptive military strikes if the United States detects an imminent launch of a intercontinental ballistic missile — maybe one intended to demonstrate the potential reach to the West Coast. Mr. Perry argued for that step in 2006, that he wrote with a future defense secretary, Ashton B. Carter. “If North Korea persists in its launch preparations, the United States should immediately make clear its intention to strike and destroy” the missile on the pad, they wrote.
But Mr. Perry noted recently that “even if you think it was a good idea at the time” — and he now seems to have his doubts — “it’s not a good idea today.”
The reason is simple: In the intervening 11 years, the North has built too many missiles, of too many varieties, to make the benefits of a strike like that worth the risk. It has test-flown a new generation of solid-fuel missiles, which can be easily hidden in mountain caves and rolled out for quick launch.
And the North Koreans still possess their ultimate weapon of retaliation: artillery along the northern edge of the Demilitarized Zone that can take out the South’s capital, Seoul, a city of approximately 10 million people and one of the most vibrant economic hubs of Asia.
In short, that is a risk the North Koreans are betting even Mr. Trump, for all his threats, would not take. “A conflict in North Korea,” Defense Secretary Jim Mattis said on CBS’s “Face the Nation” in May, “would be probably the worst kind of fighting in most people’s lifetimes.”
Which leads to the next option, the one that South Korea’s new president, Moon Jae-in, talked about in Washington on Friday when he visited Mr. Trump: negotiation. It would start with a freeze on North Korea’s nuclear and missile tests in return for an American agreement to limit or suspend military exercises with South Korea. Mr. Xi has long urged that approach, and it won an endorsement on Tuesday from President Vladimir V. Putin of Russia, after he met with the Chinese leader.
That, too, carries risks. It essentially achieves the North Korean and Chinese goal of limiting American military freedom of action in the Pacific, and over time it would erode the quality of the American-South Korean military deterrent.
Negotiating with the North is hardly a new idea: President Bill Clinton tried it in 1994, and Mr. Bush in the last two years of his term. But both discovered that over time, once the North Koreans determined that the economic benefits were limited, the deals fell apart.
Moreover, a freeze at this late date, when the North is estimated to have 10 to 20 , essentially acknowledges that the North’s modest arsenal is here to stay.
Mr. Tillerson said as much when he visited Seoul in mid-March and any solution that would enshrine “a comprehensive set of capabilities” in the North. He has since softened his public comments. Administration officials now suggest that a freeze would not be a solution, but a way station to a nuclear-free Korean Peninsula — in other words, an agreement that Mr. Kim would give up all his nuclear weapons and missiles.
But it is now clear that Mr. Kim has no interest in giving up that power. As he looks around the world, he sees cases like that of Col. Muammar el-Qaddafi of Libya, an authoritarian who gave up his nascent nuclear program, only to be deposed, with American help, as soon as his people turned against him. That is what Mr. Kim believes his nuclear program will prevent — an American effort to topple him.
He may be right.