Many observers judged the recent meeting between President Joe Biden and South Korean President Moon Jae-in a success, with the Biden administration offering a return to normalcy after four tempestuous years under President Donald Trump.

Although the two sides purported to be in sync regarding North Korea, it isn’t clear that Washington is prepared to do what Seoul believes is necessary to conciliate the Democratic People’s Republic of Korea. News that the administration planned to have its ambassador to Indonesia handle the North Korea portfolio on the side sounded like an echo of the Obama administration’s neglectful “strategic patience,” which amounted to kicking the nuclear fuel rods down the road.

The United States agreeing to remove limits on the range and payload of South Korean missiles was the summit’s most important step forward. Dating back to 1979 (and later amended), a bilateral agreement limited their range to 800 kilometers, or close to 500 miles. The purported purpose was to prevent a regional arms race.

At that time, Washington and Beijing had just completed the process of diplomatic recognition. Allowing a military ally to build missiles capable of hitting China might have harmed the newly evolving relationship. However, given the PRC’s dramatic military developments, that rationale long ago disappeared.

There’s no other good reason to prevent the Republic of Korea from matching the capabilities of other states, which are racing ahead to improve their arsenals. After all, the DPRK is developing missiles that could hit the continental United States (along with nuclear weapons for the missiles to carry). Nevertheless, Pyongyang’s reaction to the announcement was predictable: “The termination step is a stark reminder of the U.S. hostile policy toward the DPRK and its shameful double-dealing,” adding that the new policy was a “deliberate and hostile act” that could result in an “acute and instable situation.”

In an unusual development, Kim Myong Chol, an unofficial spokesman a North Korean news agency dubbed an “international affairs critic” said, “It is a serious blunder for [the United States] to pressurize the DPRK by creating asymmetric imbalance in and around the Korean Peninsula.” Washington’s action, he said, “is all meant to spark off [an] arms race … and check the development of the DPRK.”

In contrast, Beijing said little. Its ambassador to South Korea, Xing Haiming, dismissed the issue as a bilateral matter, though warned that “we will not stand still if it does damage to China’s national interest.”

Removing limits on South Korean missile development will yield two major benefits. The first will be to strengthen the South vis-à-vis the North. Although making unsubstantiated claims about lost credibility are common, the Moon government’s approach has been all carrot and no stick. Unfortunately, for Pyongyang, applying pressure on the ROK probably feels like pushing an open door.

Indeed, nothing done by the DPRK, including last year’s destruction of the liaison building built at Seoul’s considerable expense, has diminished President Moon’s ardor in courting North Korea. Worse was the Moon government seeming to follow orders from Kim Yo-jong, Kim Jong-un’s sister, in prohibiting use of balloons to send material into the North. The argument for helping the Kim dynasty build a taller wall around its people would be weak at any time, but is especially problematic when Pyongyang is refusing to engage the ROK and the United States.

Although South Korean support for diplomacy has been an important balance for Washington’s sometimes belligerence, it would be healthier if North Korea also respected Seoul’s military prowess. A stronger ROK is more likely to achieve better results in negotiating with its northern antagonist. In denouncing the possibility of an “arms race,” the DPRK obviously has taken note of South Korea’s potential. Pyongyang realizes that it can no longer improve its arsenal without consequence.

Equally important, inviting the South to expand its missile capability is a gentle push for it to take on greater responsibility for its own defense. South Koreans across the political spectrum support the alliance because it is a great deal for them: they get to borrow a superpower’s military even though their nation has long been capable of defending itself. Although Seoul bears a relatively greater burden than America’s other allies in both Asia and Europe, with more than 50 times the GDP and twice the population of the North, the South could do much more.

In this way Seoul would be improving deterrence. Most importantly, the ROK would have new and better options for retaliating against North Korean provocations. Pyongyang couldn’t assume Washington would block retaliation by the South if the latter was capable of striking multiple targets in the North. The potential for South Korea to match and even surpass the DPRK’s developments might make North Korea more amenable to negotiation.

Adding to the South’s military capabilities would also make it easier for the United States to not just share, but shift military burdens. It makes little sense that 68 years after the Korean War ended Seoul remains dependent on America. Military commitments and deployments should change along with circumstances. The Korean Peninsula is vastly different from when the “Mutual” Defense Treaty was ratified.

An improved strike capacity also would give the ROK the beginnings of a deterrent against China. Although the PRC appears to prefer influence to conquest — swallowing the proud, independent Korean people would be a stretch even for Beijing — improved armaments would add a more practical guarantee against that unlikely possibility. Indeed, the best, most certain, barrier to Chinese overreach in the region is a gaggle of well-armed neighbors sporting potent militaries. The PRC could still win any fight, but the price of aggression would be too high to contemplate seriously.

Indeed, it is increasingly urgent for America to set military priorities. The ongoing pandemic has accelerated Washington’s rapidly advancing fiscal bust. The national debt will hit 108 percent of GDP this year, breaking the record of 106 percent set at the end of World War II. With America’s aging population, that number will continue rising, and is expected to exceed 200 percent of GDP by 2050 unless Congress makes a remarkable and unexpected conversion to fiscal responsibility. Since lawmakers can’t reduce interest payments, won’t slash Social Security or Medicare, and can’t easily reverse Medicaid, the Pentagon will necessarily be on the cutting block.

Summits between the United States and South Korea tend to be judged by a single metric: Is the alliance being strengthened? Paradoxically, however, reducing America’s responsibilities is more important. The relationship is a means to an end, not an end itself. The objective of protecting America, the most important goal of any alliance, is more effectively achieved if U.S. partners take on more responsibility for their own security.

Indeed, shifting that core duty should be the ultimate objective of every military alliance that Washington joins. Then the members could better concentrate on advancing shared interests while the United States paid greater attention to where America’s greatest needs are concentrated today — at home.