Evidence that North Korea was responsible for the massive Sony hack is mounting, and in many ways the country has already been convicted in the court of US public opinion. But, no matter how conclusive the evidence becomes, one thing remains widely misunderstood: why North Korea would do this.

Despite the emerging narrative that North Korea hacked Sony Pictures in revenge for insulting Kim Jong Un with The Interview, this incident is consistent with a long line of North Korean attacks and provocations that are premised on such slights — a South Korean president saying the wrong thing, for example, or the US conducting too-close military exercises. But these are understood to be excuses, and the attacks are not responses but are in fact part of a long-running North Korean strategy carefully designed to increase international tensions.

in buying north korea's explanation, we are helping kim jong un

This is belligerence meant to deter the much stronger South Korea and US, and to draw international attention that North Korea can use to bolster domestic propaganda portraying Kim Jong Un as a fearless leader showing up the evil foreign imperialists. It is meant to foment the isolation and tension that has allowed the Kim family to hold onto rule, impossibly, for decades. It has nothing to do with Sony's film, however offensive it may be, with the film's portrayal of Kim, or with free speech in America. In believing North Korea's rhetoric strongly implying a connection, we are buying into the country's strategy and helping Kim succeed.

It's not actually about The Interview offending Kim Jong Un

There is every reason to believe that The Interview is just an excuse, and Sony just collateral damage, in yet another random act of North Korean violence made to perpetuate the international tensions that Kim Jong Un sees as serving his larger strategic interests.

The assumption is that North Korea would want to hack Sony as revenge for The Interview, a now-cancelled comedy that was to portray the cartoonishly tasteless assassination of North Korean leader Kim Jong Un. Both North Korean state media and the hackers themselves have gone to great lengths to express outrage over the film, and the hackers have in fact repeatedly suggested that this is what motivated them.

This conforms with American understandings of how North Korea works. We see it as an irrational, inherently aggressive country, run by lunatic hotheads, whom we can easily imagine flying off the handle at hearing about The Interview, especially the craziest of them all, leader Kim Jong Un. North Korean media's unhinged statements have done a lot to cement that view. That's deliberate: North Korea wants us to see them as crazy, irrational, volatile — and dangerous.

North Korea has a long, and easy to study, history of launching these seemingly random attacks or provocations. The Sony hack fits clearly into that pattern. In the past, those have been military attacks. It test-launched long-range offensive missiles, fired dangerously close to Japan, in 2005, 2006, and 2007. It shelled the South Korean island of Yeonpyeong and sank a South Korean naval ship, Cheonan, both in 2010. It set off test nuclear warheads in 2006, 2009, and 2013. It has also launched offensive cyberattacks in the past, such as against US and South Korean government targets in 2009, against South Korean banks in 2011, and South Korean banks and TV stations in 2013.

Every time, the attacks are accompanied by a spate of over-the-top rhetoric and threats, and the North makes every effort to portray itself as dangerously irrational, and an unpredictable threat to world peace. It is certainly dangerous, but it's anything but irrational or unpredictable.

The real reasons North Korea launches attacks

The effort that North Korean state media makes to convince us they're crazy gets to the three real reasons that North Korea launches these occasional attacks.

The first reason is to appear crazy and dangerous, so as to deter North Korea's far stronger enemies from doing anything against the country.

Kim Jong Un isn't stupid: he knows that his weak, impoverished state is much weaker than the US and South Korea and Japan, all of whom would just love to see his government collapse. North Korea can only deter those enemies by being more threatening and dangerous; it will never be stronger, so it has to be crazier instead, always more willing to escalate. This convinces the US and other countries, even if they see through Kim's game, that it's just easier to stay away from North Korea than to risk provoking the country into another flamboyant attack.

The second reason that North Korea does this is to keep the Korean peninsula perpetually locked in a state of high-tension and low-boil conflict, which is essential for North Korean domestic propaganda and for keeping out would-be foreign meddlers like the United States.

The country's breathtakingly oppressive government had kept power, even since the 1990s famine, with something called the Song'un or military-first policy. This policy tells North Koreans that the reason they are hungry and impoverished and locked in a police state is because this is all necessary to fund the military and protect from internal enemies, so as to keep the country safe from the imperialist Americans who would otherwise surely overwhelm them and do unspeakable things. But the Song'un policy requires keeping the appearance of a conflict with the US going at all times, which means occasionally North Korea has to lash out to maintain tensions.

The third reason is that Kim Jong Un believes he needs to keep the Korean peninsula in a state of perpetual tension and conflict to maintain his government's own physical security. This keeps the US and others on the defensive and wary of doing anything against North Korea. It also frequently generates concessions for North Korea — like Sony pulling the release of The Interview, or the US sending former Presidents Jimmy Carter or Bill Clinton to negotiate the release of Americans held by North Korea. Even if these concessions are only symbolic , they still serve North Korean domestic propaganda.

North Korea's effort to fool us is working — and The Interview proves it

Like so much of North Korea's behavior, its cyberwarfare program is another sign that, despite its popular portrayal (including in The Interview) as a wingnut state run by delusional madmen, the country is coldly rational and brutally strategic in its actions.

North Korea's decision to hack Sony is being widely misconstrued as an expression of either the country's insanity or of its outrage over The Interview. But that sort of cartoonish mischaracterization is exactly how Americans came to believe that North Korea was a bunch of buffoons who probably couldn't dial up to the internet, much less launch one of the most successful cyber attacks against the US in history.

And it is a portrayal of North Korea that is far from unique to The Interview, but that the film certainly did its part to promote, playing up the Hermit Kingdom as a hilarious and bizarre little oddity of a country, run by a crazy man.

This strategy of portraying itself as crazy is remarkably effective at securing North Korea's strategic goals. But it is also quite dangerous. By design, the risk of escalation is high, so as to make the situation just dangerous enough that foreign leaders will want to deescalate. And it puts pressure on American, South Korean, and Japanese leaders to decide how to respond — knowing that any punishment will only serve to bolster North Korean propaganda and encourage further belligerence. In this sense, the attacks are calibrated to be just severe enough to demand our attention, but not so bad as to lead to all-out war.

People will often say that North Korea launches these attacks because they're crazy or irrational. If only it were that simple, the Kim Jong Un regime would have driven itself into extinction decades ago.