Pyongyang has pledged to suspend its nuclear enrichment, but it won't last.
North Korea has pledged to halt its nuclear enrichment, nuclear tests, and long-range missile tests, which is great news. Pyongyang's nuclear program is one of the world's most dangerous threats: it risks an accidental nuclear war, raises the possibility of a conventional war, and destabilizes one of the most militarized and densely populated regions in the world. A mere gesture from Pyongyang toward cutting this program makes everyone on Earth a bit safer. And all we had to do was promise some food aid for North Koreans, which is worthwhile in its own right.
But this is not a permanent solution to North Korea's nuclear program. Even if Pyongyang does live up to the deal, they will almost certainly start the program back up in a few years. North Korea has pledged to shut down its nuclear program before, and sometimes even followed through, but they always start it back up. North Korea shut down its program in 1994 when they signed the "Agreed Framework," then revealed in 2002 that they had restarted it. They agreed in 2005 to a new deal to de-nuclearize, but the country ignored it and proceeded anyway. In between, there have been countless ups and downs, moments when Pyongyang made concessions or opened to inspectors, only to later push the inspectors out or test long-range missiles.
From Pyongyang's perspective, this erratic strategy actually makes a lot of sense. North Korea doesn't really want to use a nuclear warhead -- that would spark a U.S.-led counterattack that would destroy the country almost immediately -- they just want (1) to deter the U.S. from invading and (2) to blackmail the world into giving it the food and money it needs to survive. With the former, the regime buys external security, protection against an overwhelmingly hostile world. With the latter, it buys internal security, keeping North Korean society barely afloat and making individual citizens dependent on the state for survival.
And the rest of the world is complicit, playing North Korea's game, because we don't really have a choice. Meanwhile, whether North Korea is ramping up their nuclear program or winding it down, the underlying problem remains. The regime in Pyongyang is holding the outside world, as well as its own people, hostage in a stand-off that has now lasted decades. They don't have an out any more than we do.
Unpredictability is one of North Korea's greatest assets. This is part of why they might be willing to slow, stall, or even reverse their nuclear program: their volatility is simply a more powerful weapon. Still, there are patterns. The country signed 1994's "Agreed Framework" only a few months after Kim Jong Il took power. In retrospect, it looks as if Kim knew that his regime was unusually insecure during the transition, and that the nuclear concessions would make him more secure by holding back the outside world (why should the U.S. want to attack if it looks like Kim was willing to cut a deal?) and getting new aid for his people. In other words, looking back, it's clear that actually disarming was probably not his goal.
Today, the months-old regime of son and successor Kim Jong Un is probably playing the same trick as his father did in 1994. But one difference is that we can see the nuclear betrayal coming this time, as the U.S. State Department may have hinted in its statement calling the deal "important, if limited, progress." North Korea, we now know, will probably never truly and fully disarm of its own volition. Understanding that now, what are we going to do about it?