WASHINGTON — North Korea’s ongoing development of nuclear weapons poses an especially grave security challenge for the United States.

The most recent round of six-party talks (involving China, Russia, Japan, South Korea, North Korea and the United States) made, at best, incremental progress toward a solution to the crisis. Throughout the negotiations, the U.S. goal has remained the same: a complete, verifiable and irreversible end to North Korea’s nuclear program.

A growing number of influential Americans are dissatisfied with such a “narrow” agenda, however. Republican Sen. Sam Brownback of Kansas, Michael O’Hanlon of the Brookings Institution and Michael Horowitz of the Hudson Institute are among those who demand that the United States add North Korea’s human rights practices and the issue of regime “transformation” to the list of topics the next round of six-party talks must address. Congressional passage of the North Korean Human Rights Act last year points to a similar strategy.

That approach would be a profound mistake.

Improving the abysmal human rights situation in North Korea or achieving regime change in that long-suffering country may be desirable in the abstract, but U.S. leaders cannot let those goals interfere with the fundamental objective of the negotiations — the elimination of North Korea’s nuclear weapons capability.

A nuclear-armed North Korea threatens to destabilize the security environment in East Asia, a region of considerable strategic and economic value to the United States. Even worse, a cash-strapped North Korean regime with a surplus of nuclear weapons in its arsenal might be tempted to sell one to al-Qaida or some other terrorist organization.

Progress in the six-party talks has been difficult enough without adding issues to the agenda that the North Korean government regards as an intolerable threat to regime survival. Broadening the agenda in that fashion is almost guaranteed to torpedo any conceivable deal on the nuclear issue.

It is possible (although by no means certain) that Kim Jong Il’s regime may agree to relinquish its nuclear ambitions in exchange for a U.S. nonaggression pledge, a peace treaty formally ending the Korean War and normalized political and economic relations with Washington.

There is almost no chance that the regime will agree to abandon the repressive policies that enable it to retain political power. By making the human rights issue and regime transformation a litmus test for the six-party talks, the United States would be demanding that the North Korean leadership agree to commit political suicide.

It is the hallmark of realism that policymakers sometimes have to accept less than ideal outcomes. The United States often has had to conclude limited agreements with odious governments to advance important American interests.

Washington signed the 1963 Atmospheric Nuclear Test Ban Treaty with the Soviet Union and two decades later negotiated an agreement that pulled both countries’ medium-range nuclear missiles out of Europe. The United States did not insist that the Soviet Union become an enlightened democracy as a condition for signing those documents. U.S. interests and the cause of peace were advanced because U.S. officials were willing to accept narrow agreements instead of holding out for the wholesale transformation of the Soviet system. That outcome occurred much later and because of an array of different, mostly domestic, factors.

The United States faces a similar situation today with respect to North Korea. If it is possible to conclude an agreement for the complete, verifiable and irreversible end to that country’s nuclear threat, Washington would be foolish to jeopardize the opportunity.

Every American of good will hopes that someday the brutal North Korean regime will end up on the ash heap of history where it belongs. But the United States cannot sacrifice its security interests in an attempt to achieve idealistic (and in the near term, at least, probably unattainable) goals. To do so would be a dangerously shortsighted policy.