SEOUL (Reuters) - North Korea’s next step after rattling the world by putting a satellite into orbit for the first time will likely be a nuclear test, the third conducted by the reclusive and unpredictable state.

A nuclear test would be the logical follow-up to Wednesday’s successful rocket launch, analysts said. The North’s 2009 test came on May 25, a month after a rocket launch.

For the North and its absolute ruler Kim Jong-un, the costs of the rocket program and its allied nuclear weapons efforts - estimated by South Korea’s government at $2.8-$3.2 billion since 1998 - and the risk of additional U.N. or unilateral sanctions are simply not part of the calculation.

“North Korea will insist any sanctions are unjust, and if sanctions get toughened, the likelihood of North Korea carrying out a nuclear test is high,” said Baek Seung-joo of the Korea Institute of Defense Analyses.

The United Nations Security Council is to discuss how to respond to the launch, which it says is a breach of sanctions imposed in 2006 and 2009 that banned the isolated and impoverished state from missile and nuclear developments in the wake of its two nuclear weapons tests.

The only surprise is that the Security Council appears to believe it can dissuade Pyongyang, now on its third hereditary ruler since its foundation in 1948, from further nuclear or rocket tests.

Even China, the North’s only major diplomatic backer, has limited clout on a state whose policy of self reliance is backed up by an ideology that states: “No matter how precious peace is, we will never beg for peace. Peace lies at the end of the barrel of our gun.”

As recently as August, North Korea showed it was well aware of how a second rocket launch this year, after a failed attempt in April, would be received in Washington.

“It is true that both satellite carrier rocket and (a) missile with warhead use similar technology,” its Foreign Ministry said in an eight-page statement carried by state news agency KCNA on August 31.

“The U.S. saw our satellite carrier rocket as a long-range missile that would one day reach the U.S. because it regards the DPRK (Democratic Peoples Republic of Korea) as an enemy.”

CASH IN EXCHANGED FOR COLDER WAR

The end-game for the North is a formal peace treaty with Washington, diplomatic recognition and bundles of cash to help bolster its moribund economy.

“They might hope that the U.S. will finally face the unpleasant reality and will start negotiations aimed at slowing down or freezing, but not reversing, their nuclear and missile programs,” said Andrei Lankov, a North Korea expert at Kookmin University in Seoul.

Slideshow ( 15 images )

“If such a deal is possible, mere cognition is not enough. The U.S. will have to pay, will have to provide generous ‘aid’ as a reward for North Koreans’ willingness to slow down or stop for a while.”

Recent commercially available satellite imagery shows that North Korea has rebuilt an old road leading to its nuclear test site in the mountainous northeast of the country. It has also shoveled away snow and dirt from one of the entrances to the test tunnel as recently as November.

At the same time as developing its nuclear weapons test site, the North has pushed ahead with what it says is a civil nuclear program.

Slideshow ( 15 images )

At the end of November, the International Atomic Energy Agency (IAEA) said the construction of a light water reactor was moving ahead and that North Korea had largely completed work on the exterior of the main buildings.

North Korea says it needs nuclear power to provide electricity, but has also boasted of its nuclear deterrence capability and has traded nuclear technology with Syria, Libya and probably Pakistan, according to U.S. intelligence reports.

It terms its nuclear weapons program a “treasured sword”.

The missile and the nuclear tests both serve as a “shop window” for Pyongyang’s technology and Kookmin’s Lankov adds that the attractions for other states could rise if North Korea carries out a test using highly enriched uranium (HEU).

In its two nuclear tests so far, the North has used plutonium, of which it has limited stocks. However it sits on vast reserves of uranium minerals, which could give it a second path to a nuclear weapon.

“An HEU-based device will have a great political impact, since it will demonstrate that North Korean engineers know how to enrich uranium, and this knowledge is in high demand among aspiring nuclear states,” Lankov said.