North Korea appears headed for a fifth nuclear test. The U.S. joined South Korea and Japan in warning Pyongyang against violating its international obligations. Just as the three governments have done for the last quarter century.

Alas, they cannot stop the North from moving forward with its nuclear program, at least at reasonable cost. Washington should learn the value of saying nothing

The U.S. stands apart from the rest of the world. American officials circle the globe lecturing other nations. Yet other governments rarely heed Washington. It doesn’t matter whether they are friends or foes. Other states act in their, not America’s, interest.

Perhaps the most famous recent “red line” set by Washington was against Syria’s apparent use of chemical weapons in the ongoing civil war. However, the president’s off-hand comment promising action never made sense, since America would have gained nothing by going to war.

Syria’s death toll has reached 400,000, the vast majority from bombs and bullets. Use of chemical weapons only marginally adds to the horror. And weakening the Assad regime effectively strengthens the Islamic State.

Anyway, since 2011 the Obama administration has said that Syrian President Bashir al-Assad must go. But the administration has done little to force him out. So much for U.S. credibility.

Washington suffers the same problem when addressing its nominal friends and allies. For instance, Washington long demanded that its allies spend and do more. But most states sheltering behind America continue to do what they always did, live off of the U.S. Washington responded by doing what it always did, whine while underwriting its nominal allies. America’s complaints had no impact on its friends’ behavior.

Now North Korea is in the news again. For a quarter century U.S. presidents—Bill Clinton, George W. Bush, Barack Obama—insisted that the North cannot, must not, dare not, develop nuclear weapons. The North proceeded to accumulate nuclear materials, test nuclear weapons, miniaturize warheads, and expand missile development. Which led Washington to … insist, yet again, that Pyongyang comply with its demands.

American officials should stop making demands which they are unwilling to enforce. An occasional bluff might pay dividends, but U.S. officials will retain credibility only if they exercise restraint and reserve threats for issues of serious interest to America.

As I wrote in Conservative Review: “The world always will be unmanageable and messy, well beyond America’s control. After all, the U.S. was created by a few angry, determined colonists who took on the world’s greatest power. It should not surprise their descendants that governments and peoples elsewhere are willing to similarly defy the world’s current greatest power.”

In most cases, the U.S. should say nothing and work behind the scenes to achieve its goals. Rather than highlight its impotence, Washington should demonstrate humility and prudence, virtues too often missing in U.S. foreign policy.