Despite the success of America’s post-World War II policy, its advocates act as if it is an abysmal failure. No matter that the ROK took advantage of Washington’s defense shield to develop into one of the world’s most important, largest, and advanced economies. The U.S. must continue to protect the South from the latter’s decrepit northern neighbor.

For instance, analyst Khang Vu offers no argument that South Korea is vital for America. He refers to another Korean war posing “an adverse prospect for future U.S. administrations.”

Which is about right. It would be a human tragedy and source of instability, but it wouldn’t matter much for American security. The next step would not be conquest of the West Coast (despite the hysterical plot of the movie reboot Red Dawn).

But why would the South lose? After all, the South possesses an economy around 40 times as large and population about twice as large, and has neutralized North Korea’s two traditional military allies, China and Russia. Seoul could easily match, indeed overmatch, the so-called Democratic People’s Republic of Korea.

Yet there is fear of a power vacuum, in the belief that the South would not bother to build up its own forces. America therefore must spend more, deploy more troops, and repeatedly “reassure” its helpless allies.

Ohm Tae-am of the Korea Institute for Defense Analyses recently defended the ROK’s inadequate spending as having increased six times since 1991. But the South was starting with a very low base. Seoul is far richer than the DPRK, and therefore has no excuse for claiming it cannot defend itself.

Still, maybe the ROK would not expand its forces while the U.S. was withdrawing its units. Probably not, but even that would be Seoul’s decision. It makes no sense to force the American people to defend the South Korean people if the latter aren’t willing to defend themselves.

However, Vu warns that the South might irresponsibly respond “militarily to avoid losing face” to a DPRK provocation. Thus, American troops must remain on station to prevent Seoul from doing something stupid. If Seoul is truly that irresponsible, Washington should disengage immediately.

Of course, Vu says, don’t worry, “the presence of American troops has effectively thwarted North Korean attacks in the first place.” However, deterrence frequently fails.

Moreover, the chief danger on the Korean peninsula is not aggression but mistake. It is impossible to deter misjudgment. If something goes wrong, the U.S. will find itself automatically involved in someone else’s war.

Vu also makes the curious claim that defending the world costs America nothing because Seoul helps pay basing costs. However, foreign policy drives force structure. If Washington did not promise to defend the South, and a multitude of other states, it could shrink the armed forces. So the cost of protecting the ROK is not just the expense of basing units overseas, but of creating them in the first place.

Finally, critics dismiss the likelihood that U.S. disengagement would advance negotiation. In fact, it seems unlikely that Pyongyang would yield its existing nuclear arsenal under any circumstances, but there are other potentially useful deals that could be struck, including limiting future nuclear developments and reducing conventional force deployments.

Of course, positive results remain unlikely. But just doing what we’ve been doing isn’t likely to get better results in the future.

Ultimately, North Korea threatens America only because America threatens North Korea. If U.S. troops weren’t stationed on the peninsula, Kim would find other targets for his abundant venom and threats.

America remains in Korea out of habit. Which has helped turn the Pentagon into a vast fount of international charity.

As I point out in National Interest: “South Korea is one of America’s many foreign welfare dependents. The U.S. military is overstretched. The U.S. government is effectively broke. The American people are overwhelmed with debt.”

It’s time for Washington to pare back unnecessary security commitments. Allowing the ROK to defend itself would be a good place to start.