PYEONGTAEK, South Korea -- The "center of gravity" for the defense alliance between South Korea and the U.S. is a massive military base built on acres of former rice paddies.

Nowadays, the talk of the town on the facility is the possibility of major changes in the nature of Seoul and Washington's defense partnership. A long-rumbling question between the allies is when South Korea might retake authority to command troops in the event of an armed conflict, known as wartime operational control, or OPCON.

The base, called Camp Humphreys, is the biggest overseas U.S. military installation in the world at around 3,500 hectares. It is a roughly 90 minute drive south of Seoul in a strategic location across the Yellow Sea from China and hosts around 20,000 U.S. soldiers in what looks like an American suburb with wide streets punctuated with fast food joints.

Despite the high-level chatter, authorities on the base focus their daily efforts on keeping soldiers as content as possible, providing a broad range of familiar food and recreation options, from Arby's and Popeyes to a bowling alley and video game consoles. On a rare press tour on Wednesday for reporters from foreign media outlets, Jeff Nagan, the base's public affairs director, said making the far-off installment feel like home is a strategic priority.

Soldiers that eat and sleep in comfort are more effective on the battlefield, he said. "That's going to help [their] ability to 'fight tonight' if the flag goes up," Nagan said. An overhead view of the Camp Humphreys U.S. military base in Pyeongtaek, South Korea.

Since the 1950-53 Korean War, the U.S. has held OPCON, which has meant that if North Korea were to attack, a U.S. general would hold authority over South Korean troops involved in battle. Many in South Korea, particularly on the political left, have long argued that as a sovereign country, it should be able to command its own troops at all times.

Since taking office in June of last year, left-leaning President Lee Jae Myung has made a series of strong statements about wanting to fulfill the goal of taking OPCON within his single five-year term. On Oct. 19, Lee told reporters, "To put it bluntly, OPCON must be returned promptly," and also said that discussions with the U.S. were proceeding toward that end. Though as a progressive Lee's politics are markedly different from those of U.S. President Donald Trump, on the matter of OPCON the two have seen their views dovetail.

Trump has long wanted to reduce U.S. military commitments overseas and has called on allies like Japan and South Korea to handle more of their own defense. But the U.S. military officials directly involved in defending South Korea from nuclear-armed North Korea have struck a cautious tone on the question of transferring OPCON.

Speaking at a seminar in Washington earlier this month, U.S. Forces Korea Commander Xavier Brunson said that he does not oppose the OPCON transfer, but implied that due to the evolving threat environment in East Asia and recent North Korean missile launches, South Korea still has some distance to go before being "fully mission capable." Soldiers get set for a training exercise on the Camp Humphreys U.S. military base in Pyeongtaek, South Korea, on Oct. 28. Lee's political adversaries in the conservative opposition People Power Party have criticized his OPCON stance as premature and a potential risk to national security.

PPP floor leader Kim Tae-kyu called Lee's plan to take over OPCON within his term "reckless" and accused the president of treating the transfer as a political endeavor instead of a carefully considered process managed by both countries' militaries. If the OPCON transfer goes ahead, structural changes would come for the military alliance.

Under the current arrangement, Brunson heads the two nations' Combined Forces Command, with a South Korean general serving as deputy commander. Were OPCON to be transferred, a new structure would have to be created, with a South Korean general in charge, flanked by an American deputy commander, according to Park Hwee-rhak, a retired professor at Kookmin University in Seoul. Instead of rushing to take over OPCON, Park argues that it is incumbent on the government to work with the U.S. to figure out exactly how the Combined Forces Command would function post-transfer.

"If the Combined Forces Command is left up to the South Korean military, they need to explain to the public what means and what methods they would use to deter North Korea's nuclear weapons," Park said. A bowling alley is among recreational facilities available to personnel stationed on the Camp Humphreys U.S. military base in Pyeongtaek, South Korea.

On the ground at Camp Humphreys, officials would not comment on the record regarding the official discussions over OPCON or how affairs on the base would be affected.

They instead focus on duties like soldier training. U.S. forces from regional bases in Japan and Guam fly in to learn skills such as emergency rescue, helicopter piloting and marksmanship.

One room features life-like dummies in a dark, smoke-filled room where soldiers learn to safely evacuate incapacitated comrades. In another, a military jeep is set up that trainers can flip 180 degrees while soldiers are inside. The soldiers' task is then to egress the vehicle from an upside-down position.

South Korean soldiers belonging to a special unit that augments U.S. forces, called KATUSA, take part in many such exercises. Nagan stressed that cooperation between Americans and South Koreans on the base continues in its usual comradely atmosphere.

"Political divides don't matter," Nagan said. "The Korean people know that we're here serving our nation and they want to help."