As Presidents Lee and Obama reaffirm the relationship and celebrate congressional approval of a long-pending free trade deal, they must also focus on difficult challenges ahead with North Korea and China's rise, say experts.

Even if a U.S. assessment of North Korea's food situation echoes a UN report earlier this year that warned of shortages, debate rages about whether new food aid should be provided to a recalcitrant Pyongyang.

This issue guide provides a range of background and analysis on Japan's earthquake, tsunami, and nuclear crisis.

As Japan struggles to control problems at the Fukushima Daiichi plant, it also must grapple with questions about nuclear power in the face of immediate and long-term energy needs.

With the nuclear incident at the Fukushima power plant unabated, Japanese officials have come under fire for failing to control the crisis as concern about radiation grows.

An unfolding nuclear crisis in the aftermath of Japan's earthquake and tsunami is raising questions over safety of nuclear power, and could bring expansion of nuclear power projects globally under pressure.

North Korea's strike on Yeonpyeong Island is part of a military escalation designed to strengthen the authority of leader-in-waiting Kim Jong-Un, say experts, and underscores Washington's frustrations with Pyongyang and Beijing.

A meeting of North Korean officials is expected to signal succession to Kim Jong-Il. Experts say the power transition is unlikely to herald reforms, and urge efforts to engage with the regime.

Korean Peninsula tensions are high, in part fueled by U.S.-South Korea joint military exercises. Experts say the United States must continue to work toward North Korea's denuclearization and prepare for volatility with a leadership change in Pyongyang.

A compilation of resources on the impact of the global financial crisis on Japan.

North Korea has resisted efforts to divulge the full scale of its nuclear program, despite U.S. concessions, but President-elect Barack Obama faces little alternative to the troubled policy of engagement.

U.S. financial regulators could draw some lessons from Japan's experience of the 1990s, when the implosion of a real estate bubble led to a systemic crisis in the country's banking sector.

The latest declaration from North Korea has brought rewards from Washington but experts say bigger challenges lie ahead.

Seoul's conservative government is struggling to reconcile its foreign policy goals with the popular sentiments of its people.

Washington’s latest revisions to its stance on North Korea nuclear-disarmament talks, experts say, threatens to undermine counter-proliferation efforts.

A conservative parliament may provide further impetus to South Korean president to maintain a harder line on Pyongyang.

North Korea’s missed deadline on its denuclearization pact and new tough rhetoric revive concerns about the regime’s sincerity and stability.

The conservative front-runner won South Korea’s December 19 elections. His policies could test relations with North Korea.

A mysterious Israeli air raid in Syria has led to speculation that North Korea is outfitting Damascus with nuclear material.

The election of a veteran politician raises as many questions as it answers in a country brimming with political uncertainty.