Who started it? The question recalls juvenile disputes between siblings or classmates, but at the moment it's the issue at the center of the increasingly puerile Republican presidential primary. Did Donald Trump or Ted Cruz start the fight over each other's wives? One thing is for sure: Cruz has not gone after or been a part of any attack on Trump's wife Melania. Anyone who claims otherwise is either woefully uninformed or buying into the falsehoods perpetuated by Trump himself or his campaign surrogates.

It's worth going through the timeline on this story. On March 21, the day before the Utah caucuses and Arizona primary, BuzzFeed's McKay Coppins reported on Facebook ads being seen by voters in those states encouraging Republicans to vote against Trump. The ads were paid for by a super PAC called Make America Awesome, a group created by Republican strategist Liz Mair for the sole purpose of fighting Trump. Make America Awesome is almost laughably small — by the end of February, the group had raised just under $19,000 since the beginning of the year.

The offending ad features a provocative seminude photo of Melania Trump (before she had married Trump) from a 2000 photo shoot for GQ magazine. "Meet Melania Trump. Your next first lady," the text on the ad reads. "Or, you could support Ted Cruz on Tuesday."

On Tuesday evening, just as it became clear Trump was going to be crushed by Cruz (and in fact, come in third behind John Kasich) in Utah, the GOP frontrunner took to Twitter.

Lyin' Ted Cruz just used a picture of Melania from a G.Q. shoot in his ad. Be careful, Lyin' Ted, or I will spill the beans on your wife! — Donald J. Trump (@realDonaldTrump) March 23, 2016

The first part of this message is simply untrue. Cruz had not "just used a picture of Melania." Not even one of the several super PACs supporting Cruz "used a picture of Melania." As the ads themselves clearly state, they were paid for by Make American Awesome.

Let me write that again, at the risk of redundancy: Neither Cruz, nor a super PAC supporting him, used Melania's photo shoot or anything about Melania in a way to attack her or Trump's campaign. The Make America Awesome PAC may have been encouraging voters to vote for Cruz as a vote against Trump, but that does not make it the responsibility of Cruz. "Our activities are solely intended to defeat Donald Trump," a representative of the PAC told the Washington Examiner. All this is worth emphasizing and repeating because many in the media have falsely claimed the ad was somehow connected to Cruz. But, it must be repeated, it was not.

"But," several Trump supporters on TV and social media have protested, "Cruz never denounced the ad." Again, it's an ad that neither Cruz nor anyone explicitly supporting him created. But it would be the decent thing to do. So why didn't the Texas senator denounce it?

Well, he did, the next morning, at a press gaggle in New York. "Look, that ad was completely inappropriate," Cruz said before pointing out that it was in no way connected to him, his campaign, or his supportive super PACs. Cruz has repeatedly called for wives and children of candidates to be left out of the campaign rhetoric and has praised Melania Trump herself as an "incredible mom."

It was Make America Awesome, not Ted Cruz, that criticized Melania Trump. That hasn't stopped Trump and his surrogates, like campaign spokeswoman Katrina Pierson, from drawing a connection that isn't there and falsely stating Cruz did not denounce the ad.

Why does all of this matter? Because of the second part of Trump's Tuesday night tweet, which escalated things from a tasteless targeted Facebook ad to an actual attack from Trump on his opponent's wife. Trump cryptically claimed Cruz's wife Heidi Cruz had something to hide and that he would "spill the beans" on her.

And as cable news increased the coverage of the new spat between the two candidates, Trump upped the ante late Wednesday night by retweeting an image of side-by-side photos of his wife and an unflattering photo of Heidi Cruz. "A picture is worth a thousand words," read the original tweet.

The creator of the photo was clearly inspired by Trump's Tuesday tweet because the image references Trump's "spill the beans" phrase.

And Team Trump appears to be on board. Pierson declined to denounce the Trump photo. So did another campaign adviser, Stephen Miller. "There was a vicious, mean-spirited, uncalled-for attack on Mr. Trump's wife, and it was a personal attack about her image and appearance," Miller told CNN Thursday. "And so he responded as any normal person would. I don't really understand what the concern is."

Emails to prominent Trump supporters like Scott Brown, who has a wife and two daughters, and Sarah Palin, who has three daughters and as a woman herself has faced similar attacks about her looks, have gone unanswered.

To briefly summarize: A small organization of citizens with the sole purpose of stopping Donald Trump paid for online ads that used a publicly available photograph of Trump's wife to attack him. Trump responded by incorrectly attributing the ads to Cruz and then attacking Cruz's wife, a message that reached an exponentially larger number of people than the targeted Facebook ads. Cruz defended his wife, defended Trump's wife, and denounced the original ad, with which he had nothing to do. Trump responded to this by tweeting out to his millions of followers an unflattering photo of Cruz's wife. And Trump supporters have either tacitly approved of Trump's attack or ignored it.

The whole episode was the equivalent of a Red Sox fan heckling a Yankees pitcher from the stands and the pitcher in turn throwing a fastball right into the Red Sox batter's face. There's no equivalence here. There's no "Trump-Cruz feud" over each other's wives. The anti-Trump super PAC may have "started" the fight, but the responsibility for escalating the attacks to beyond the bounds of decency falls, as it often has in this election, on Trump and Trump alone.