When considering recent North Korean promises of devastating military strikes against the United States and South Korea, it’s important to understand that Pyongyang carries out its threats — except when it doesn’t.

Despite this, it’s probably best not to take any chances.

Once again, North Korea is pushing tensions in Northeast Asia to a fever-pitch. In addition to military action, Pyongyang is ending the 1953 armistice as well as shutting down the DMZ crisis hotline.

It’s done things like this before, but this time North Korea is annoyed about new punitive economic sanctions the United Nations levied on it last week as a result of its recent nuclear explosion.

Pyongyang may also feel emboldened in light of that (likely) more advanced nuclear weapons test — and a successful long-range ballistic missile launch that preceded it.

But beyond the new U.N. sanctions, North Korea is also doing lots of messaging with its threatening words and behavior. First, it’s trying to pump up the leadership credentials of Kim Jong Un to his own people.

When he came into office, the newest king of the “Kim-dom” didn’t have the gravitas of his grandfather and the nation’s founder (Kim Il Sung), or his father (Kim Jong Il), a long-standing No. 2 and later leader.

And nothing burnishes a North Korean cult of personality like chest-thumping its archenemies, South Korea and the United States, in the state-run media.

Of course, the messages go beyond the folks at home.

North Korea can’t be any too happy with China, which supported the newest U.N. sanctions. Beijing and Pyongyang have a curious marriage; while a regional crisis doesn’t benefit China, North Korea feels it must show its independence from time to time.

Plus, Pyongyang wouldn’t mind causing some trouble for the new government in Seoul under South Korea’s first female president, Park Geun-hye, who came to power just last month.

North Korea hasn’t been afraid to mix it up militarily with South Korea in recent years, including sinking one of its warships and shelling a South Korean island.

Naturally, North Korea is also signaling to President Obama’s new national security team, including Secretary of State John Kerry and Defense Secretary Chuck Hagel that it won’t be taken for granted.

Considering ongoing and future U.S. defense cuts, Pyongyang may feel the time is right to tweak Washington’s nose.

So, in the end, North Korea makes threats. It thrives on its ability to wreak death and destruction. Some threats they carry out; some they don’t. When and where is also their choice.

The problem is that if they don’t carry threats out, they become meaningless, losing their leverage. It’s best we err on the safe side and be ready for trouble.

-Peter Brookes is a Heritage Foundation senior fellow and a former deputy assistant secretary of defense.