South Korean President Park Geun-hye is in Washington this week as the third of President Obama’s summit trifecta with Northeast Asian leaders. She has the opportunity to address growing regional security challenges and reassert an important Korean role on the world stage.

When I attended President Park’s inauguration in 2013, I stated that I had “every confidence that she would carry South Korea's success and the relationship with the United States to new heights.” Two years later, I believe my confidence was well-placed.

Indeed, South Korea is a beacon of leadership for so many other nations aspiring to greater security and prosperity for their people. And it plays a critical role in advancing freedom in the region.

When I first traveled there in the early 1970s, gross domestic product per capita was less than $2,000. Over the past four decades, South Korea has achieved truly remarkable economic development, reaching GDP per capita of over $30,000. Today, as a dynamic, free market democracy, South Korea's innovative and vibrant economy is among the world’s 30 freest in The Heritage Foundation’s Index of Economic Freedom.

This week’s summit follows a number of notable accomplishments over the past years. Washington and Seoul have already put into practice a bilateral free trade agreement, revised and expanded alliance guidelines, implemented new contingency plans for North Korean provocations, and signed an updated civilian nuclear agreement.

North Korea’s recent provocations have pushed the regime to the top of items to be discussed between Mr. Obama and Ms. Park. Pyongyang did not launch a long-range missile on Oct. 10 to celebrate the 70th anniversary of the founding of the Korean Workers Party, as some had predicted. But it is only a matter of time before the regime does so, once again violating numerous U.N. resolutions.

When it does, Mr. Obama and Ms. Park should coordinate a common response by calling on the U.N. Security Council to press for stronger, more effective sanctions. There are also numerous targeted financial measures that the U.S. has yet to impose on Pyongyang.

Washington should publicly affirm its commitment to use all necessary means to defend our important ally against its despotic neighbor to the north. U.S. allies worldwide have begun to question American resolve after devastating cuts to our defense budget and unfulfilled “red lines” of commitment.

There should be no doubt in Seoul’s — or Pyongyang’s — mind that the U.S.-South Korean alliance forged in the crucible of war remains just as strong and unbreakable today. The North Korean military threat overshadows another tragedy on the Korean Peninsula: the plight of the North Korean people. They suffer under the scourge of human rights violations so widespread, systemic and egregious that a U.N. Commission of Inquiry concluded they constituted “crimes against humanity.”

Despite 18 months since the release of the U.N. report, the Obama administration has not taken any action. The U.S. has sanctioned zero — yes, zero — North Korean entities for human rights violations, and the South Korean legislature remains mired in a decade long debate over whether to approve a North Korean Human Rights Act. The North Korean people deserve better.

Ms. Park’s firm response to a North Korean military incursion in August included reinstituting broadcasting information into North Korea along the Demilitarized Zone. Pyongyang’s strong response showed how sensitive it was to its citizens being exposed to truth from the outside world. Mr. Obama and Ms. Park should discuss ways in which the allies can use the power of information to induce reform — as was done against the Soviet Union during the Cold War.

But South Korea is more than just an ally. It is a strong U.S. partner in addressing an array of global security threats as well as diplomatic opportunities. Though a small nation, South Korea has frequently “punched above its weight” on the world stage.

That is why Mr. Obama and Ms. Park should look beyond the Korean Peninsula to discuss ways in which the U.S. and South Korea can further nurture the vital partnership around the globe.

-Ed Feulner is founder of The Heritage Foundation.