President Park Geun-hye enters her fourth year in office this week with bigger trouble from North Korea and a broader challenge in regional diplomacy.

The communist neighbor's back-to-back provocations roiled the security conditions in Northeast Asia, a major spot for rivalry and cooperation between the United States and China.

Inter-Korean ties have also been rocked by the North's Jan. 6 nuclear test and a long-range rocket launch a month later. 

Military tensions are escalating. All cross-border exchanges have come to a grinding halt. The Kaesong Industrial Complex has been shut down.

Park's signature Korea Trust-Building Process is in tatters.

Her "unification bonanza" vision is doubtful.

In a special parliamentary address last week, Park declared a shift in her focus on North Korea from engagement to pressure.

She even talked about "regime collapse," something of a taboo for South Korean leaders in their public remarks.

Pundits say inter-Korean relations are expected to remain icy throughout the remainder of her term that ends in early 2018.

"Until the end of the Park Geun-hye administration's tenure, the confrontational mode, rather than dialogue, will likely continue," Kim Yong-hyun, professor at Seoul's Dongguk University, said.

The North's provocations have also complicated the Park government's diplomacy.

It has especially driven a wedge between Seoul and Beijing, upending much of what Park did in the past three years.

She attended China's key war anniversary event less than half a year ago, demonstrating her resolve to build a bilateral strategic partnership.

Despite her efforts and personal ties with President Xi Jinping, China has been lukewarm toward imposing painful new sanctions on the North. Beijing has emphasized the need for dialogue as well instead of a sanctions-only approach.

China and Russia are fiercely opposed to South Korea's move to bring the U.S. THAAD advanced missile defense system to the peninsula.

Some observers argue that Northeast Asia is gripped by a New Cold War.

Concerns are growing over the fallout from the strain in the Seoul-Beijing relationship.

Even if a U.N. Security Council resolution is adopted to punish the North, chances are slim that it will move toward denuclearization.

"That's a reason why South Korea should bear in mind coordination and cooperation with neighboring countries over the long term," said Chang Yong-seok, senior researcher at the Seoul National University Institute for Peace and Unification Studies.

"In that sense, strategic communication with China is of importance."

The Park administration is also faced with the daunting task of faithfully implementing a landmark verbal deal with Japan on the "comfort women" issue. Political debates go on ahead of the general elections in April.

In spite of a formal apology and offer of financial support for the victims, the Shinzo Abe administration denies the forced nature of its sexual enslavement of hundreds of thousands of Korean women during World War II.

Many say the problem will continue to dog Park amid controversy over the "final and irreversible" accord. (Yonhap)