The problem with the strategic doctrine of "mutually assured destruction" (MAD), which, it is argued, prevented nuclear exchanges during the Cold War, is that while it may deter actual attack through fear of annihilation, it does little to discourage the escalation of warmongering rhetoric. Threats must be met by counterthreats even if, as with North Korea's current sabre rattling, both South Korea and her guarantor, the US, are ultimately convinced that Pyonyang, no matter what she might say, will not step over the line.
To make the counterthreat credible security must be ramped up, armies put on alert, missiles targeted, and the civilian population put on a semi-war footing. And there is always that niggling doubt about whether the North is the “rational” actor that MAD doctrine presupposes. Is it just possible that a demented Pyonyang, its economy and authority crumbling, would stake all on one last desperate throw of the dice?
In recent days, exasperated by military exercises in the South, Kim Jong Un's regime, which conducted its third nuclear test in February, has re-declared war on the South ( although the civil war's hostilities ended in 1953, the war was never declared over) and has threatened nuclear attacks on the US (which its missiles can not yet reach). Yesterday, worryingly, North Korea also announced plans to restart a mothballed nuclear reactor at the Yongbyon nuclear plant, closed since 2007 as part of a de-nuclearisation deal. A newly released speech by Kim, however, refers to the country's armoury simply as a "a reliable war deterrent".
The Yongbyon move in particular represents a real blow to its only real ally, China's hopes of restarting de-nuclearisation talks on the Korean peninsula, and prompted Beijing to express regret at the decision.
Such bouts of North Korean megaphone diplomacy and attention-seeking are all too familiar, but nerve-wracking for the South, expensive to respond to, and, when prolonged as they are currently, the danger is that one side will stumble accidentally into a bloody clash that could all too easily escalate.