Housewives haven’t been the only South Korean women to toil for the pleasure of American soldiers in the ensuing decades. As detailed by Katharine Moon in her authoritative study “Sex Among Allies: Military Prostitution in U.S.-Korea Relations,” the South Korean military dictatorship coerced women into sex work for American soldiers. Survivors testified to forced testing for sexually transmitted diseases and treatment while in confinement, all for the health and happiness of our protectors.

Then there is the Status of Forces Agreement, signed between the two nations in 1966 and renewed twice. It has been understood to grant the United States military nearly exclusive jurisdiction over its personnel, such that even high-profile offenses committed by American soldiers against South Korean citizens go unpunished.

One of the most heinous examples happened in 2002 when an American military vehicle ran over two middle-school students, crushing them to death. The perpetrators were shielded from South Korean authorities and a United States military court dismissed the case.

More recently, the United States military has refused to take responsibility for its environmental degradation of its base in central Seoul.

Being an ally has also meant deploying soldiers for America’s wars — to Vietnam, where some 5,000 South Koreans died and many suffered from exposure to the United States-made chemical weapon known as Agent Orange; and to Iraq in the 2000s, despite enormous local protests. Government officials from that time have explained that the Iraq deployment came in response to the Bush administration’s threat to reduce the number of Americans stationed in South Korea.

But the biggest cost of the alliance has been the erosion of South Korea’s sovereign spirit. There is enormous support among South Koreans for the United States military presence, and it isn’t simply a reflection of national goodwill toward America. It speaks volumes about just how much South Korea has become psychologically dependent on a foreign army as a potential barrier against North Korea, despite an annual national defense budget amounting to about 2.7 percent of its G.D.P. and a nearly 650,000-strong military.

Washington knows full well that stationing its soldiers on South Korean soil isn’t an act of charity. America offers protection, but only in return for influence over its lesser allies’ affairs.