Once again the world has seen – through its fourth nuclear bomb test – how unpredictable North Korea is and how difficult it is to rein in the rogue state.

This time the North claimed that they had successfully detonated a hydrogen bomb and therefore that the country has reached a higher stage of development of nuclear weapons and joined the advanced ranks of nuclear weapons states.

South Korea and the world should brace for greater tension on the Korean Peninsula and beyond as the provocation – an obvious violation of U.N. Security Council resolutions – will draw further international sanctions. As President Park Geun-hye said, the North must pay the price for its reckless action.

As it did in the past, the North may not easily give in to new sanctions and pressure and instead will try to ratchet up tensions by threatening or executing further provocations such as launches of long-range missiles.  

North Korean leader Kim Jong-un, who indicated the development of a hydrogen bomb last month, was shrewd to not refer to the nuclear weapons program in his New Year’s address. This of course was aimed at maximizing the effect of the surprise blast, which caught South Korea and its allies off guard.

It is not difficult to guess why the young dictator of the reclusive country is running the risk of fresh international sanctions and deteriorating relations with its neighbors, including China, once its close ally whose influence the North still cannot ignore. 

By elevating its threat of nuclear force, the North is trying to secure a stronger position in its dealings with South Korea, the U.S. and the international community.

Internally, Kim, stepping into his fifth year in power, apparently wants to solidify his grip on the country by building his image as a capable leader. This is all the more necessary because he has yet to show his countrymen any notable achievement in the economy. It also should be noted that the Congress of the Workers’ Party – the first of its kind since 1980 -- is scheduled for May.

Whatever motivation Kim may have, the fourth nuclear test tells us that threats from the North’s weapons of mass construction are real. The North is striving to miniaturize nuclear warheads and develop long-range missiles, including those launched by submarines. The worst case would be the North succeeding in developing missiles with nuclear warheads.

Presiding over an emergency National Security Council meeting, Park said that North Korea should pay a price for the test. This was echoed by other leaders like U.S. President Barack Obama and Japanese Prime Minister Shinzo Abe. 

In close consultations not only with the allies but also China and the U.N., Park needs to work out realistic countermeasures against the North’s provocation.

The first step could be agreeing on sanctions that can inflict real pain on the regime in Pyongyang.