North Korea has grabbed international headlines. Again. Pyongyang staged its 4th nuclear test, supposedly a thermonuclear device.

Proposals for more sanctions and further isolation likely will grow. However, the test dramatically demonstrated that the U.S. attempt to build a cordon sanitaire around the Democratic People’s Republic of Korea has failed.

Washington instead should develop a new policy focused on engagement, not denuclearization. The latter should remain an objective, but even if it remains out of reach the U.S. might be able to reduce military threats on the peninsula.

As always, North Korean foreign policy reflects domestic politics. The test also gives Pyongyang greater leverage in its attempt to engage both South Korea and the U.S.

Talks with the Republic of Korea recently ended without result. The North also long has sought to draw the U.S. into bilateral discussions. However, the Obama administration set as a precondition for any talks that Pyongyang take steps toward dismantling its nuclear program, a non-starter.

In dealing with the North there are only second-best options which might ameliorate the threat otherwise posed by a famously enigmatic, persistently paranoid, and potentially unstable nuclear-armed state viewing itself in a perpetual state of war with America and its allies, South Korea and Japan.

The possibility of Pyongyang amassing not only a sizeable nuclear arsenal, but a thermonuclear arsenal, should help concentrate minds in Washington.

Current policy has failed. But more military threats would merely reinforce the case for nuclear weapons to North Korea. Moreover, the North recognizes that Washington has little stomach for a real war with mass casualties.

Additional sanctions aren’t likely to work without Beijing’s support. Xinhua News Agency ran an editorial criticizing the test, but urging “various parties” to “exercise restraint to prevent conflicts from escalating.”

Even if Beijing allows passage of a new UN Security Council resolution condemning the North, China is likely to limit the impact of any new sanctions. The PRC wants neither a messy national implosion on its border nor a united Korea hosting U.S. troops that could become part of an American containment network directed against the PRC.

Moreover, the DPRK has reopened channels to Russia. Although Moscow condemned the test, growing North Korea-Russia ties will discourage China acting against the DPRK.

The status quo has nothing to recommend it. North Korea will expand its nuclear and missile programs. Tensions will steadily rise. Any conflict will become more destructive.

Which leaves engagement.

Demanding denuclearization first ensures failure. As I wrote for Forbes: “Pyongyang is unlikely to abandon its weapon that best deters a U.S. attempt at regime change on the Korean peninsula. A nuclear arsenal has the additional advantages of preserving independence amidst other major powers (China, Japan, Russia), winning international stature for an otherwise minor, impoverished state, and offering abundant opportunities to extort economic and other benefits from fearful neighbors.”

In contrast, engagement at least creates the possibility, though admittedly small, of future denuclearization. First, negotiating with the North is the best way to reduce its fear of an American preventative war and detail the potential economic and diplomatic benefits of abandoning nukes.

Second, reducing U.S. threats against the DPRK would satisfy China’s standard response when urged to apply greater pressure on Pyongyang. Fair or not, the PRC long has blamed Washington for driving the North toward nuclear weapons.

Talking with the DPRK might achieve nothing. But Washington might be pleasantly surprised. Even if Pyongyang refused to eliminate its existing arsenal, the Kim regime might make other concessions, such as limiting future nuclear activity and reducing conventional threats.

So far nothing has stopped Pyongyang from developing nuclear weapons. Continued attempts at coercion aren’t likely to yield a better result.

As has oft been said, a good definition of insanity is doing the same thing while expecting a different result. Which leaves engagement as the best option for dealing with North Korea.