D.C. Mayor Muriel Bowser delivered an apology to the residents of the District after the city failed to adequately prepare for an inch of snowfall Wednesday, which caused significant delays during rush hour. (WUSA9)

As we’ve proved before, we’re not good at snow. And on Wednesday night, we proved it again in utterly humiliating fashion, morphing from a powerful city of powerful people into a demolition-derby, wagon-training cold mess.

A one-inch snowtastrophe involving at least 1,000 accidents, eight-hour commutes and cars abandoned on freeways by desperate, disgusted commuters. Some people hadn’t even made it home by dawn Thursday.

Our commander in chief was equally powerless in the face of the fluff, as it took his lights-and-sirens motorcade nearly two hours to make the usually 30-minute commute from Joint Base Andrews to the White House.

It was a nearly perfect deja vu of a light snow in 2011 that generated epic Twitter travelogues of misery. Only difference this time? It was more fun to Snapchat the whole calamity.

Frustrated D.C. drivers took to social media to document their commuting woes on Jan. 20. Light snow fell and caused traffic jams and minor crashes on busy, slick roads. (Jenny Starrs,Victoria Walker/The Washington Post)

Didn’t we learn a thing back then? Apparently not.

Scarier still: A monster snowstorm is expected to arrive Friday. It’s never good when The Post’s Capital Weather Gang issues a blizzard warning and predicts high winds and two feet of snow.

We were so fixated on the impending snow doom that we weren’t expecting Wednesday night’s little prelude. Too busy rescheduling meetings, raiding every market’s supply of milk, bread and wine, arguing over cute names for the coming storm and holding news conferences about preparation.

It’s the preemptive strike that destroyed us. Isn’t that always how it goes? A little ragtag band of soldiers executes a sneak attack and brings down a great fighting force by outflanking it.

Where’s the War College for snow preparation? Shouldn’t we get it in the loop? Because we desperately need a better strategy for these annual sneak attacks from the skies.

While everyone was preparing for the snow, dispatching trucks to the outer ’burbs, amassing a snow army of shovelers to keep the sidewalks clean, a quick little clipper of precipitation came in and soaked the roads, which became ice rinks once the temperatures dropped.

The roads turned to black ice because they were untreated. One set of officials said they didn’t treat them because the mini-storm was predicted to be no more than a squall. Others said that predictions called for temperatures so low that the pre-treatment they squirt on roads would freeze, making them more dangerous.

What happened to good-old road salt for conditions like this?

Sure, it’s easy to Monday-morning-quarterback this whole thing.

The District’s mayor apologized.

“We’re not a snow town.”

Oh, wait. That was Marion Barry in 1987, when D.C. was paralyzed in the snow (and he was at the Super Bowl in L.A.).

“The snow has fallen. It’s not going to be gone until the temperature gets warm enough that it can melt.”

Oh, wait. That was Adrian M. Fenty in 2010, after Snowmageddon crippled the city.

“I don’t control the weather. I don’t control the roads. I control the work schedule.” [It was] “the fastest-accumulating storm I’ve seen in my lifetime.”

Oops. Silly me, that wasn’t even a mayor. That was OPM Director John Berry in 2011, explaining the snow disaster of Mayor Vincent C. Gray’s tenure.

“Hindsight is certainly 20-20. But we are certainly going to review all of the information, when it came in and the decisions that we made.”

Oh, wait. Right mayor, wrong storm. That was Muriel E. Bowser last year, when she took heat for keeping schools open when some folks were slip-sliding all over the place.

She apologized again on Thursday: “We are sorry for an inadequate response. We did not provide the resources, and we should have been out there earlier.”

So what have mayors learned year after year of the snowstorm/we-freak-out/we-forget/snowstorm/we-freak-out cycle? To apologize. And that seems to be about it.

Bowser and other public officials vowed to do better. But the truth is, it’s a national disgrace and an ongoing embarrassment that we are so bad at dealing with snow. We spend a bazillion dollars on military drones and planes to deploy stealth strikes, yet the heart of all our operations can be crippled by a single inch of white crystals.

It makes little municipal sense to bust a budget on a Midwestern-style snow force. But the federal presence here should command a more muscular response. Every couple of years, we lose millions in federal workforce hours, insurance, school closings. Wouldn’t it be worth it to finally get this right?

We’re all worried about ISIS when the truth is, all it takes to destroy us is a little ice.

Twitter: @petulad