Nikki Haley, the U.S. ambassador to the United Nations. (Hector Retamal/AFP/Getty Images)

This op-ed has been updated.

As sabers rattle ever louder across fields, plains, oceans and deserts, President Trump’s words from this year haunt the stable mind:

“I would love to be able to bring back our country into a great form of unity,” he said. “Without a major event where people pull together, that’s hard to do. But I would like to do it without that major event because usually that major event is not a good thing.”

So true, Mr. President, so true.

Trump made these remarks to a gathering of television anchors a few hours before his first State of the Union address in January . Lamenting the country’s divisiveness, harking back to the impeachment of President Bill Clinton, he noted that Americans usually unite during troubled times. A common enemy is helpful.

What could be more unifying than World War III?

As the U.N. Security Council called an emergency meeting Friday to discuss Syria, much of Washington was riveted on excerpts from pre-publication copies of James B. Comey’s new book, “A Higher Loyalty,” in which the former FBI director, whom Trump fired, gives his version of events leading up to both the 2016 presidential election and his eventual pink slip.

The consensus of most early readers was that the book amplified little in the legal sense, but there were other morsels to chew over regarding Trump’s ethics, such as immediately trying to figure out how to spin the information Comey had just delivered about Russian interference with the election, and his being “untethered to truth.” A few offhand observations about the president’s appearance — “shorter than he seemed on a debate stage,” white circles under his eyes suggesting tanning goggles, and an overlong tie — were surely intended to get under the president’s skin. So much for the long-awaited tell-all.

Then came Friday night. The United States, acting in concert with Britain and France, fired cruise missiles at three sites linked to Syria’s chemical weapons program. Russia had earlier promised to counterattack American interests should the United States attack Syria in response to the Assad regime’s reported chemical attack April 7 in Douma, which was said to have killed dozens of civilians, including children, but there was no immediate indication of escalation, at least. Russia implausibly insists the chemical attack was staged by Britain. No one really thinks that, though, and Trump advisers argued that now was the time to act definitively and dust off our shock-and-awe manual. On Friday, Nikki Haley, the U.S. ambassador to the United Nations, laid the blame at Russia’s feet. “It is Russia alone that agreed to be the guarantor of the removal of all chemical weapons in Syria,” she said.

This remark was perhaps also intended as a direct strike against former president Barack Obama, who, instead of enforcing his own red line on chemical weapons during his time in office, agreed to an arrangement with Russia guaranteeing elimination of the Syrian regime’s chemical arsenal. That Bashar al-Assad and Russia failed to keep their word should surprise no one.

Also unsurprising is the president’s on-again, off-again bellicosity.

In 2013, Civilian Trump was apoplec­tically ALL-CAPS TWEETING his disapproval of Obama’s weakness in the same position he finds himself now. Later, Candidate Trump painted himself more as an isolationist than as a crusader ready to wage war to protect the 1997 Chemical Weapons Convention outlawing the use of those types of weapons.

Unless, that is, a blistering act of international chivalry might benefit him personally. One prays this wouldn’t be the case, but there’s little in the president’s history to suggest a higher loyalty. Biographer Jon Meacham recently said that although Trump speaks ideologically, his only true ideology is of himself.

In other words, one fears that the question before us ultimately could be: How would taking out Assad benefit Trump?

There may be every reason to begin preparations for a finale, but this takes time because of coalition building, positioning air and naval assets, drafting allies in the Arab world and, one hopes, averting war with Russia. Uneasily, we recall Iraq — and the day after. We could decimate Syria, but then what? Who fills the void? The Islamic State? Iran? ­Hezbollah? Russia? If we were ultimately “successful,” would we be initiating yet another long-term occupation in the Middle East?

The lowing, somber sounds of drums rolling along Pennsylvania Avenue, where Trump is planning to stage a dramatic military parade, seemed not so distant this week. Unless Trump and Putin are playing a blind man’s bluff, restful sleep eludes a world in which the U.S. commander in chief — obedient only to an ideology of self — believes that it would take a “major event” to bring America back together.

Read more from Kathleen Parker’s archive, follow her on Twitter or find her on Facebook.