In South Korea, only a democracy since 1987, a “reverse January 6” has happened. Instead of storming the legislative building to undermine democracy and interfere with the results of a free and fair election—as in the United States and Brazil—protesters helped South Korean lawmakers swarm past armed troops to end President Yoon Suk Yeol’s short-lived attempt at martial law.

It is hoped the perpetrator of this power grab to exterminate the young democracy will be evicted, in one way or another, from office in short order.

In any case, such political instability should raise questions about the continued stationing of 30,000 U.S. troops on South Korean soil. They may have been needed after the Korean War (1950-1953) to prevent North Korea from invading the then-poor South Korea again. However, South Korea has undergone an economic miracle in the ensuing seven decades while the communist and chronically destitute North Korea has undergone periodic famines.

South Korea now has a GDP that is 60 times that of the North and should be able to defend itself.

Yet, South Korea routinely underspends on its military because it has a shield of U.S. nuclear and conventional weapons protecting it. The United States, which has a staggering national debt of 36 trillion and rising, must encourage its wealthy allies to make more significant efforts for their defense, as they soon may be pressured to do when Donald Trump takes office.

Trump should first announce that over five years, the United States would gradually withdraw all 30,000 troops, which now act as just a tripwire for a massive U.S. intervention if North Korea attacks the South again. During those five years, South Korea would be incentivized to spend more on defense and rapidly upgrade its already capable military forces.

Because any North Korean invasion would need to proceed down mountain valleys into the South, it should lessen the difficulty of defending against such an attack. North Korean invasion forces would be very vulnerable to attack from the air in those confined areas as they move South—being caught in a shooting gallery.

North Korea has a large, lumbering military, but well-to-do South Korea has, or can buy, much better military technology. Communist North Korea, which has been impoverished by a dysfunctional economy, has trouble doing either.

Critics of such a change in U.S. policy argue that the United States turning over more defense responsibilities to South Korea might result in South Korea going nuclear to match North Korean nuclear weapons capabilities. Spanning authoritarian and democratic governments over the decades, South Korea has always been a responsible player internationally, as has Japan.

Under Joe Biden, Japan and South Korea—two U.S. allies that have been mutually suspicious of each other because of Japan’s past treatment of South Korea before and during World War II—have now reconciled. If either one of those upstanding countries became nuclear powers to better defend themselves against China and North Korea, it would not be the worst thing that ever happened because they likely would have a deterrent from attack independent of the United States.

Also, by giving wealthy South Korea (and maybe Japan) incentives to do more for their defense, U.S. security policy in East Asia could be more flexible. A lower-key U.S. approach to the static defense of South Korea—perhaps as a balancer of last resort in a dire emergency—could allow more U.S. attention to prodding Taiwan to augment its defenses against perhaps a more acute threat from China.

Even after withdrawing U.S. forces from South Korea, the United States could arrange a base-access agreement that U.S. military forces could use in any dire regional emergency—for example, during any general war with China. South Korea would certainly have an incentive to agree to such arrangements.

Finally, deployed U.S. forces definitely should not get involved in any internal suppression of dissent or violence in South Korea. Such disturbances could find them. In short, South Korea can remain a nation friendly to the United States without 30,000 U.S. troops being stationed there.