What will it take to stop North Korea?

Why does North Korea hate the US?
Why does North Korea hate the US?

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    Why does North Korea hate the US?

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Why does North Korea hate the US? 01:53

John Everard is a former British ambassador to North Korea. The opinions in this article belong solely to the author.

(CNN)Despite Donald Trump's tweet back in January, it has happened. The missile that North Korea test-launched on Independence Day was an intercontinental ballistic missile, according to US Secretary of State Rex Tillerson. It could very probably reach Alaska.

North Korea has probably not yet mastered two key technologies -- how to miniaturize a warhead (small bombs are more difficult than big ones) and how to get a missile back through the atmosphere without it spinning out of control or burning up. But with a missile of this range, North Korea is dangerously close to being able to credibly threaten a nuclear strike on an American city.
How can this be stopped?
The North Korean leadership seems to believe that its nuclear and missile programs are vital to its survival. It is convinced (is it wrong?) that when it can credibly threaten to obliterate an American city, Washington will no longer dare to seek its overthrow, nor will the US attempt to reinforce its South Korean ally, should North Korea attempt to reunify the peninsula by force.
    It has stated clearly and repeatedly that its nuclear and missile programs are not bargaining chips to be negotiated away. And it has ridden out sanctions, even tough ones, rather than give up the programs
    The logic is clear but chilling. If the regime believes that nuclear weapons -- and the missiles to carry them -- are vital to its survival, only a threat to its survival greater than that posed by the absence of nuclear weapons would persuade leader Kim Jong Un to abandon his drive for a nuclear deterrent.
    Broadly, there are two such possible threats.
    Firstly, the international community could pile on sufficient economic pressure to convince the regime that unless it abandons these programs, its economy will collapse and it will face a dangerous domestic revolt.
    As more than 90% of North Korea's trade is with China, this approach would only work with the active support of that country -- and President Trump would doubtless try to convince Chinese President Xi Jinping of this when they meet Thursday in Hamburg.
    New video shows N. Korea launch ICMB missile
    New video shows N. Korea launch ICMB missile

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      New video shows N. Korea launch ICMB missile

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    New video shows N. Korea launch ICMB missile 00:50
    But China has many very good reasons for not wanting to push North Korea to the brink of collapse and is unlikely to turn the screws that hard.
    Secondly, the US could credibly threaten serious military action against North Korea unless it gives up its programs.
    But a war in North Korea would be unspeakably horrible. Although it might be possible quickly to seize North Korea's major cities, the country's military might well fight to the bitter end.
    North Korea would be likely to use its stocks of the nerve gas -- with which it killed the unfortunate Kim Jong Nam -- and, of course, it has nuclear weapons.
    So neither option is good and, although either might work, neither is sure to do so. North Korea survived the famine of the 1990s without collapsing, and the regime might calculate that it could survive the same again.
    Since North Korea knows that the US knows just how unattractive the military option is, it would be very difficult for Washington to convince Pyongyang that it was serious about it. Pyongyang might simply ignore these threats and continue on its current path, regardless.
    This is looking bad. The world long ago ran out of good options for dealing with North Korea. We are now stuck with two that are both dangerous and uncertain to succeed.
    And with every launch and every nuclear test, the chances rise that North Korea will get its deliverable bomb.