The sequence of events is familiar. As was the case in 2006 and 2009, a North Korean launch of a long-range rocket draws rebukes from the UN. North Korea reacts furiously to the opprobrium and raises the stakes, threatening to carry out a nuclear test. If the past is anything to go by, a nuclear test will indeed follow.

The assessment of North Korea's neighours is that the regime has been preparing for its third test for some time, after spotting evidence of new tunelling at the scene of the 2006 and 2009 tests. It is possible that the bomb test was intended for last year to mark the centennial of the birth of Kim Il Sung, the founder of the dynasty, and the first year in power of his grandson, Kim Jong-un. But the much trumpeted launch of the Unha-3 rocket in April failed spectacularly, exploding seconds after take-off and falling into the sea.

A second test launch was carried out in December, much earlier than expected - the test launch season is usually spring to summer - suggesting that Pyongyang was in a hurry to catch up on a planned schedule. The ostensible goal was to launch a weather satellite but the technology is fundamentally the same as an intercontinental ballistic missile, which North Korea is banned by the UN Security Council from developing.

Today's bellicose announcement by the national defence commission comes just a day after the UN Security Council condemned the launch, extended sanctions and threatened "significant action" in the event of further missile or nuclear tests. The speed of the North Korean riposte suggests strongly that the move is a piece of choreography planned long in advance.

The rhetoric about the targeting of a forthcoming test and further missile launches at the US stands out this time. It seems likely that the combative choice of words is intended to grab attention in Washington which has largely taken a laid-back approach to North Korean sabre-rattling under the perhaps optimistic rubric of 'strategic patience'.

It is the latest cycle in a now establish pattern of dysfunctional behaviour, by which the international community attempts to condition North Korean behaviour by imposing punishment on Pyongyang for transgressions, and North Korea hits back with dramatic actions intended to persuade the international community, the US particularly, that while it might respond positively to carrots - in the form of cash, fuel, recognition and security guarantees - the use of sticks will always backfire. It is a pattern destined to escalate.

If there is indeed a third nuclear test, one of the important questions will be whether the nuclear warhead detonated is made of plutonium, like the first two, or weapons-grade uranium (WGU). If it is the latter, it will mean that North Korea's enrichment programme has succeeded in making WGU, an advanced technical achievement, and Pyongyang will henceforward have two routes to making a bomb, and the potential for a further larger arsenal that the 6-18 warhead-worth of plutonium currently estimated in its stockpile.