I'm Sure You Know This, But Just in Case You Don't ...

When the Washington Post reports that ...

North Korea will be able to field a reliable, nuclear-capable intercontinental ballistic missile as early as next year, U.S. officials have concluded in a confidential assessment that dramatically shrinks the timeline for when Pyongyang could strike North American cities with atomic weapons. ... The DIA has concluded that North Korean leader Kim Jong Un will be able to produce a "reliable, nuclear-capable ICBM" program sometime in 2018, meaning that by next year the program will have advanced from prototype to assembly line, according to officials familiar with the document.

... what the Post is really reporting is that we're being prepped with propaganda to justify a US attack on North Korea.

That doesn't mean the attack will happen. It just means that we're being conditioned to accept it as absolutely, regrettably necessary if it does happen, in exactly the same way and for exactly the same reasons that we were told about Kuwaiti babies being thrown out of their incubators in 1990, Saddam having a chemical weapons program circa 2003, Iran being within six months of having a nuclear weapon (for 20 years running), etc.

My best guess:

• North Korea probably doesn't even have a true nuclear weapon yet. They've tested some old-timey fission weapons like those dropped on Hiroshima and Nagasaki in 1945. Max yield, 30 kilotons at the outside. Will they get a real nuke in the next year? I suppose it's possible, but I wouldn't count on it. A fission weapon is pretty forgiving. If you mash two pieces of fissile material together hard and fast enough, in a fairly simple container, you'll get the fission chain reaction you want. An H-bomb is orders of magnitude more complicated. A whole bunch of stuff has to happen in exactly the right order, at exactly at the right time, and within very narrow measurements, for the thing to work.
• Even if North Korea does have a working fusion weapon (unlikely) and even if North Korea  does have a missile capable of reaching the US (not terribly unlikely but not certain either), putting those two things together and expecting the former to detonate successfully at the end of the latter's flight isn't a task on complexity par with changing the oil in a 1966 Impala. It's complicated too.
• Pegging the likelihood that North Korea will be able to "field a reliable, nuclear-capable intercontinental ballistic missile" and the nuke to put on it by next year at one in a million is wildly optimistic (from their perspective).

The "assessment" is moonshine, and the "leak" is one of the pre-approved ones I allude to in today's Garrison Center column. The entire purpose of both is practical politics a la HL Mencken.