North Korea, which has conducted two nuclear tests in the past, is alarmingly provocative. It has recently proclaimed itself a nuclear weapons state in defiance of the international community’s demand that it dismantle its nuclear weapons program.

It has also picked out President Lee Myung-bak and news outlets in Seoul as potential targets for a “holy war of retribution.” As if to demonstrate its resolve, it sends its jet fighters threateningly close to the Demilitarized Zone before calling them back.

South Korea, which has been continuing to build up its arsenal, is not sitting idly by. Instead, it has deployed its own fighters for possible interceptions as soon as the North Korean fighters cross what it regards as the “tactical action line.” It also vows to engage the North with immediate retaliation against any military provocation.

As inter-Korean relations become increasingly hostile, a South Korean think tank says the security situation on the Korean peninsula is the worst since North Korea conducted its first nuclear test in 2006. As military allies, South Korea and the United States will have to address the precarious security situation when the Korean foreign and defense ministers have joint consultations with their U.S. counterparts in Washington this week.

The North has become confrontational since April, when it test-launched a long-range missile only to witness its destruction in mid-air. The failure must have been all the more painful to young leader Kim Jeong-un, given that he had intended the missile test to crown the centenary of his grandfather, Kim Il-sung.

A humiliated North described itself as a nuclear weapons state in its revised constitution -- an unmistakable indication that it had no intension of abolishing its nuclear weapons program in exchange for potentially massive aid from five countries participating in denuclearization talks with North Korea.

In early May, North Korea demanded that the president and conservative South Korean newspaper companies make a final choice between apologies for their critical remarks and reports and a “holy war of retribution.” While setting the coordinates for the Blue House and the newspaper companies, the North warned of precision-targeting them with “strategic missiles.”

The harsh rhetoric was followed by the frequent flights of SU-25 and other fighter jets close to the DMZ. They prompted the South Korean Air Force Command to scramble its fighters for possible interceptions.

Such provocative remarks may be nothing but childish tantrums North Korea is throwing against the Lee administration, which, unlike its predecessors, has stopped providing it with massive aid. Still Seoul cannot afford to brush them aside as such, given the deadly military actions Pyongyang has taken in the past -- including the torpedoing of a South Korean naval vessel and the shelling of a South Korean island in the west sea. Instead, South Korea needs to ensure that any such military provocation will be met with a massive retaliation.

For its part, the North will have to think twice before engaging in a military action against the South again. The South Korean military is on a standing order to strike back with double or triple the level of firepower with which the enemy has launched an attack.

Moreover, South Korea has reportedly bolstered the defenses on its islands in the West Sea, including the one that sustained North Korea’s artillery attack, with precision-guided missiles purchased from Israel. South Korea is also in the process of purchasing 367 cluster bombs from the United States for $325 million, each of which, when dropped, releases bomblets over a wide area against such targets as tanks, bunkers and parked aircraft.

With tension escalating on the Korean Peninsula, the South Korean foreign and defense ministers are scheduled to meet jointly with their U.S. counterparts in Washington on Thursday. High on the agenda will be North Korea’s military threat against the South and its claim to be a nuclear weapons state.

In wrapping up the talks, the two allies will have to issue a stern warning in clear terms against any military provocation from the North. The North may be tempted to start a military adventure unless it is convinced that such an ill-advised action will lead to its demise.