How to halt North Korea's rocket launches? Ban imports of cognac

North Korea's decision today to proceed with a controversial long-range rocket launch in defiance of a warning from its key ally, China, contains two lessons for the international community.

The first is that China's influence over its isolated and paranoid protégé remains limited on matters of national security. The second is that, with consecutive North Korean leaders apparently believing that nuclear weapons guarantee the regime's survival, there is no obvious way to persuade Pyongyang to surrender its nuclear weapons capability, despite its agreeing to do so in the past.

Today it is clearer than ever, after the North Koreans succeeded in launching an intercontinental ballistic missile and placing a satellite in orbit, that North Korea sees its nuclear weapons programme as an insurance policy against attack.

Significantly, the rocket was fired into space only days before the first anniversary of the death of the North Korean leader Kim Jong-il. It will boost his successor, Kim-Jong-un, whose youth had raised hopes of reform. He is likely to be strengthened internally following a humiliating failed test last April when a North Korean missile broke apart a second after lift-off.

Firing a satellite into outer space is not illegal. China noted as much in its reaction in which the Chinese foreign ministry spokesman, Sun Hong Lei, pointed out that North Korea's right to conduct the peaceful exploration of space was "subject to limitations by relevant UN resolutions". Using ballistic missile technology – which is required for delivering a nuclear payload – violates international law as laid down in resolutions of the UN Security Council, which met last night in emergency session to react to the launch.

The launch was greeted by strong condemnation, including by the UN Secretary-General Ban Ki-moon, a former South Korean Foreign Minister, who branded it as a "provocative act" in clear breach of UN resolutions.

But, with China holding back from a full-throated condemnation, the "consequences" threatened by North Korea's neighbours and by the United States are hard to predict.

Withholding aid is hardly a sanction in a totalitarian country whose leaders care nothing for the plight of their malnourished people and hold to a policy of "military first". One of the UN sanctions that hurt Kim Jong-il the most was said to be a 2006 resolution which banned the import of his favourite Hennessy cognac by halting the shipment of luxury goods to North Korea.

An alternative would be the imposition of unilateral sanctions. The US Treasury has played hardball with both North Korea and Iran through the banking system in the past. In 2005 the Treasury Department froze $24m in North Korean assets at the Macau-based Banco Delta Asia, accused of money-laundering for the Pyongyang élite. But that backfired when Pyongyang stormed out of six-party talks in which it had been negotiating curbs on its nuclear programme.

Other measures might be envisaged by Japan or South Korea, which are the partners of the US, Russia and China in the moribund six-party framework with North Korea, and whose leaders were particularly incensed by today's events. But unilateral measures are unlikely to enhance security and predictability in such an unstable region.

There is one constant however in North Korea's behaviour. Over the years it has consistently demanded bilateral talks with Washington. Who knows whether President Barack Obama, now in a second term with his presidential legacy to consider, will over-ride the hawks in Congress and ditch his policy of "strategic patience" with North Korea. Mr Obama won the Nobel Peace Prize in 2009 for his stance on nuclear disarmament. Now he has the chance to earn it.