Three words are often used to succinctly describe the tight bond between the U.S. and South Korea: We go together.
The phrase has long held special meaning on the Korean Peninsula, where more than 28,000 U.S. service members currently serve alongside their Korean allies.
Now, seven decades into the alliance, the three words carry added significance. "We go together" denotes a durable partnership between the two nations and a pledge to continue to stand together in the face of pressing challenges.
"Over the past seven decades, our alliance has grown stronger and more capable, and the cooperation between our people, our commitment to one another has grown deeper across every aspect of our partnership," President Joe Biden said in April as he welcomed South Korean President Yoon Suk Yeol to the White House for an official state visit marking the 70th anniversary of the alliance.
Biden said the tried-and-true partnership offers proof of a "future filled with unimaginable opportunity and endless possibility."
"Nothing — nothing — is beyond our ability to reach when our nations and our people stand united," he said. "We have proven that time and again over the last 70 years."
The alliance traces its roots to the devastation caused by the Korean War.
On June 25,1950, North Korean troops, backed by China and the Soviet Union, stormed across the 38th parallel, the line of demarcation separating Republic of Korea to the South and the Democratic People's Republic of Korea to the North.
Concerned by the brazen communist aggression, the United Nations Security Council authorized, for the first time, the formation of a multi-national force to repel further invasion from the north.
The U.S. provided most of the troops that made up the multinational U.N. Command. The U.S. Army deployed a total of eight divisions to the peninsula throughout the 37-month war.
More than 33,000 U.S. troops were killed and 103,000 wounded in fighting that lasted until the July 27, 1953, Korean Armistice, which ceased hostilities and established a Demilitarized Zone along the 38th parallel.
Yoon honored those American's who sacrificed their lives in defense of the Korean people as he spoke on the sun-drenched South Lawn in April during his official arrival ceremony at the White House.
"Why did they sacrifice their lives for this faraway country and for the people they never met? That was for one noble cause: to defend freedom," Yoon said.
"The ROK-U.S. alliance was forged in blood as a result of our fight for freedom," he said. "The ROK-U.S. alliance is not a transactional relationship; it does not operate for the sake of mere interest. The ROK-U.S. alliance is an alliance of values, standing together to safeguard the universal value of freedom."
Despite the cessation of hostilities between North and South Korea brought on by the 1953 armistice, a peace treaty has never been signed.
Following the armistice, the U.S. and South Korea signed a Mutual Defense Treaty which, to this day, underpins the alliance between the two countries.
Under the treaty, the U.S. committed to aiding South Korea in the event of an attack and has maintained a continuous presence of land, air and sea forces on the peninsula capable of responding to North Korean aggression.
To date, the U.S. remains as South Korea's foremost defense partner and the two countries have for years completed large-scale, combined exercises aimed at enhancing joint operability and deterring provocation in the region.
South Korea has also been a key U.S. partner in conflicts abroad, deploying troops in support of U.S.-led efforts in Vietnam, Iraq and Afghanistan.
South Korea holds Major Non-NATO Ally status with the U.S., entitling them certain benefits in terms of trade and security cooperation.
In 1978, the two countries formed the Combined Forces Command which formalized the U.S. and South Korean joint planning staff developed in the late 1960s as an adjunct to the United Nations Command and United States Forces Korea.
The CFC serves as the warfighting headquarters with operational control over more than 600,000 servicemembers representing both nations. The command stands ready to provide coordinated defense through combined air, ground and naval forces on the peninsula should it come under attack from the north.
Since its formation, CFC has conducted major field training and command post exercises including Ulchi Freedom Guardian, an annual drill that trains CFC personnel through state-of-the-art wargame simulations.
The U.S. and South Korean joint drills have also included combined live-fire exercises that mobilize thousands of U.S. and South Korean troops and hundreds of weapons systems.
In a joint communique issued by U.S. Secretary of Defense Lloyd J. Austin III and South Korean Minister of National Defense Lee Jong-Sup following the 54th Security Consultative Meeting between the U.S. and South Korea, the two sides pledged to continue enhancing their combined exercises to strengthen the alliance's readiness in the face of increasing provocation by North Korea.
"We still face ongoing challenges from North Korea, including its dangerous and destabilizing missile testing program, and from others who would undermine the rules-based international order," Austin said in April as he welcomed Yoon to the Pentagon during his visit to Washington.
Austin underscored that the U.S. commitment to South Korea remains "ironclad."
"The ROK and the United States have a shared vision rooted in freedom, democracy and the rule of law," he said. "Our alliance stands as a pillar of a free and open Indo-Pacific and I'm confident that we will move forward together, and I look forward to charting an ambitious path to advance our shared priorities in the Indo-Pacific."
During, Yoon's latest visit to Washington, the two countries outlined new steps aimed at bolstering the longstanding U.S.-South Korean defense alliance in the face of growing nuclear threats posed by North Korea.
Under the newly unveiled "Washington Declaration," the two countries have committed to engaging in deeper dialogue and information sharing efforts and announced the establishment of a nuclear consultative group to strengthen nuclear deterrence efforts on the Korean Peninsula.
Biden called the declaration a "prudent step" toward deterrence and in response to North Korea's advancing nuclear threat and a symbol of the U.S. unwavering commitment to South Korea.
"As our troops say, who still proudly serve together in the ROK to this day: 'We go together'," Biden said on the South Lawn. "May we continue that refrain of the Republic of Korea and the United States for all the days ahead."