“Egregious” is how United States Secretary of State John Kerry has described North Korea’s reckless international provocations, including brutal executions of people who incur the wrath of leader Kim Jong-un.

North Korea began the New Year by detonating a nuclear device Pyongyang describes as a hydrogen bomb. Apparently, that is an exaggeration but the event nonetheless is ominous.

While visiting South Korea last May, Secretary Kerry emphasized a North Korea test of a submarine launched ballistic missile was clear evidence of disinterest in joining the international community. He spoke at a joint press conference with South Korea Foreign Minister Yun Byung-se, rightly underscoring the close long-established alliance between our two nations.

In moving forward, Washington should be guided by two fundamental considerations. First, for years North Korea has been characterized by erratic, inconsistent behavior. Second, effective defense against nuclear missiles now becomes even more important.

In 2013, North Korea announced a “state of war” with South Korea and threatened nuclear attack. Pyongyang abruptly abrogated the 1953 armistice agreement ending the Korean War, and cut the military “hot line” communications link with the south.

North Korea also temporarily prevented South Korean workers from entering the Kaesong industrial center, located six miles north of the DMZ.

But there was no war, Kaesong was reopened, and Pyongyang made positive moves including reunion of previously separated families. The now well-established pattern of inconsistency may signal power struggles below Kim Jong-un.

In May Kerry also publicly mentioned the possible deployment in South Korea of the Lockheed-Martin THAAD (Terminal High Altitude Air Defense) system. In 2013, the Pentagon expanded anti-ballistic missile defenses on the U.S. West Coast. Simultaneously, THAAD was sent to Guam, a potential target. In 2009, THAAD was sent to Hawaii for the same reason.

Along with South Korea, Kerry visited China for discussions with senior foreign policy counterparts. The talks were reportedly positive and avoided THAAD deployment, strongly opposed by Beijing.

Opposition is understandable, but China should not be allowed a veto over essential national security needs of South Korea – and the U.S. Publicly raising THAAD deployment again is prudent, as a deterrent to any temptation in Pyongyang to attack either South Korea or eventually the United States.

Beyond deterrence, opportunities exist for further positive cooperation in Northeast Asia. These continue despite regular scare headlines regarding North Korea’s extreme and threatening behavior, and China’s military buildup and maritime provocations.

South Korea’s substantial investment in and trade with China grows, while North Korea remains a costly, dependent though fellow communist state. China President Xi Jinping visited Seoul soon after taking office. He has not visited North Korea.

China’s foreign policy reflects calculated self-interest, and a long history of caution regarding the use of military force. North Korea is an economic drain and a military source of worry.

The Pacific region overall provides a promising context for positive international cooperation. The Trans-Pacific Partnership trade negotiations are successful so far, and reflect an expanding framework to facilitate steadily growing trade and investment across the vast region.

South Korea President Park Geun-hye has remained calm and consistent in emphasizing strong military defense and also the possibilities for cooperation. She personifies South Korea as a formidable, effective – and sensible U.S. ally.

Secretary Kerry deserves credit for dedicated effort, disciplined negotiations and phenomenal energy, demonstrated not only in East Asia but on a global basis. A final year in office can confirm outstanding leadership.

Arthur I. Cyr is Clausen Distinguished Professor at Carthage College and author of “After the Cold War.” He can be reached at acyr@carthage.edu