Dan Janison Melville. N.Y. Tuesday January 26, 2010. Daniel Janison,

Dan Janison has been a reporter at Newsday since 1997.

Suddenly last week, a leak came from unnamed sources of the most explosive kind of security information — and its release brought no gripes from President Donald Trump & Co.

No wails of “fake news” followed, no threatening of sources. Not this time.

Duplicity has surrounded leaks forever, certainly in previous presidencies. Politically, it always depends on what got out, who released it, and who benefits to determine whether the regime in charge will approve or disapprove.

But the posture on display doesn’t usually switch this quickly. The reason is clear in this case: Hostile dictator Kim Jong Un, who perpetually threatens the United States, was reported to have miniaturized warheads for the missiles he likes to brandish.

Four days before The Washington Post and other big media sites broke this piece of what was collectively presumed to be real news, Attorney General Jeff Sessions and National Intelligence Director Dan Coats put on a somber show.

“We are taking a stand. This culture of leaking must stop,” Sessions proclaimed Aug 4. “We will not allow rogue anonymous sources with security clearances to sell out our country any longer.”

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“If you improperly disclose classified information, we will find you,” Coats warned, and prosecutions would follow.

These warnings drew instant praise from the “leak”-vexed president, who has presided over a sieve-like White House.

By last Tuesday, however, Trump himself was retweeting a scantily sourced Fox News report about North Korea moving missiles onto boats.

Awkwardly, the president’s itchy Twitter finger caught United Nations Ambassador Nikki Haley still reading from the anti-leak page. The report contained classified information, she said, and “I can’t talk about anything that’s classified.”

Hours later, a significant story followed, the one reporting Kim Jong Un’s new warhead capabilities. Without trying to detail what’s confirmed or what wasn’t, Trump used the story to launch his “fire and fury” warning, which prompted a more specific North Korean threat against Guam.

The Post attributed the story to the conclusions contained in a “confidential assessment” by “U.S. intelligence officials” that the Defense Intelligence Agency completed last month.

As always, there are leaks, and then there are leaks. The issue is always who does the leaking and why.

Consider the disclosure of Donald Trump Jr.’s meeting last year in which he was apparently promised “dirt” on Hillary Clinton. His dad tweeted: “While all agree the U.S. President has the complete power to pardon, why think of that when only crime so far is LEAKS against us. FAKE NEWS.”