Donald Trump has turned his back on pretty much everything he has ever said about United States military involvement in Syria and launched nearly 60 missiles at an air base in the country.

Trump’s official statement claimed that the strikes were in response to Syrian President Bashar al-Assad’s monstrous chemical weapons attack against his own people. But the statement also went further into the fiction of fear often touted to buttress humanitarian missions: “It is in this vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons.”

This has echoes of the George W. Bush warning about Saddam Hussein’s “weapons of mass destruction,” a lie that led us into a near decade-long war.

Not to be indelicate here, but atrocities happen in the world all the time (and have happened on an even larger scale before in Syria). Humans are capable of unimaginable cruelty. Sometimes the victims die quickly and are made visible by media for the world to see. Other times, they die in slow motion, out of sight and out of mind. Sometimes banned weapons are used; sometimes conventional weapons; sometimes, neglect, isolation and starvation.

And the world in general, and America in particular, has a way of being wishy-washy about which atrocities deserve responses and which ones don’t. These decisions can be capricious at best and calculated camouflages for ulterior motives at worst.

Indeed, the motivations for military action needn’t be singular at all, but are often multiple, tucked one inside the other like nesting dolls.

Acts of war can themselves be used as political weapons. They can distract attention, quell acrimony, increase appetite for military spending and give a boost to sagging approval ratings.

This “rally-around-the-flag” (or “rally”) effect is well documented by pollsters.

As Gallup wrote in 2001 after the attack of 9/11: “In the wake of the terrorist attacks Tuesday, American approval of the way President George W. Bush is handling his job has surged to 86 percent, the fourth highest approval rating ever measured by Gallup in the six decades it has been asking Americans to make that evaluation. Only Presidents George H. W. Bush and Harry Truman received higher ratings — the elder Bush twice during the Gulf War, with 89 percent (the highest ever) and 87 percent ratings, and Truman with 87 percent just after the Germans surrendered in World War II.”

It’s easy to sell the heroism of a humanitarian mission or the fear of terror or the two in tandem, as Trump attempted in this case.

The temptation to unleash America’s massive war machine is seductive and also addictive. Put that power in the hands of a man like Trump, who operates more on impulse and intuition than intellect, and the world should shiver.

The problem comes when the initial glow dims and darkness descends. We punch holes in some place on the other side of the world and the war hawks — many beholden to the military-industrial complex — squawk and parade about with chests swollen.

But, feeding the beast of war only amplifies its appetite. Market Watch reported last week, “It could cost about $60 million to replace the cruise missiles that the U.S. military rained on Syrian targets Thursday night,” but Fortune reported that shares of weapons manufacturers, as soon as they began trading Friday, were “collectively gaining nearly $5 billion in market value.”

War is a business, a lucrative one.

Americans, who rightly are appalled by the images of dead children, applaud. They feel proud to slap the hand of a villain without risking American bodies. But now American might is irrevocably engaged. Our thumb is on the scale, and our reputation on the line.

Often, action begets more action, as unintended consequences sprout like weeds.

In the most extreme cases, we take down a bad leader in some poor country. In theory, this helps the citizens of that country. But in the complex reality that we have had to keep learning over and over in recent history, it often creates a vacuum where one bad man can be replaced by even worse men.

We are then already in waist-deep. We have to make an impossible choice: stay and try to fix what we broke or abandon it and watch our nightmares multiply.

Nobility of the crusade is consumed by the quagmire.

This is why we would all do well to temper the self-congratulatory war speeches and thrusting of pom-poms of our politicians and pundits, some of whom hypocritically opposed the use of military force by President Obama following an even worse chemical attack in Syria in 2013.

As righteous as we may feel about punishing Assad, Syria is a hornet’s nest of forces hostile to America: Assad, Russia, and Iran on one flank and ISIS on another. You can’t afflict one faction without assisting the other. In this way, Syria is a nearly unwinnable state.

We’ve been down this road before. Just over the horizon is a hill: Steep and greased with political motives, military ambitions, American blood and squandered treasury.

Being weary here isn’t a sign of weakness; to the contrary, it’s a display of hard-won wisdom.