CLEVELAND – You know it's not a good sign for your convention if the emerging theme is "What did they know, and when did they know it?"

And yet as the Republican National Convention draws to its inevitable close Thursday night, that query is increasingly dominating the week. Ted Cruz pointedly and stunningly gave a speech wherein he refused to endorse his nemesis, the Republican presidential nominee Donald Trump, prompting attendees to ask: What did the Trump-ites know and when did they know it? This after the same question had focused since Monday night on the Melania Trump plagiarism scandal.

The result has been an angry, muddled mess of a convention, a fiasco memorably described by Politico's Glenn Thrush as a "nuclear dumpster fire." Not since Spinal Tap got lost backstage has a Cleveland production been so epically mismanaged.

Take the Cruz snub. Convention delegates and Trump campaign officials alike reacted with fury, raining boos and opprobrium down on the Texas senator. "He committed political suicide," Trump lawyer Michael Cohen said on CNN Thursday morning, calling Cruz "a baby."

But what did the Trumpites know and when did they know it? Cruz told Trump earlier this week that there would be no endorsement, the Texan's strategist told the Associated Press. And the Republican National Committee sent out an embargoed copy of Cruz's remarks well before he spoke. So this was not a surprise. What were they thinking?

"Allowing Clint Eastwood [to] speak when the Romney camp didn't know what he would say was a sin of omission," one GOP strategist says, referring to the renowned actor's bizarre turn at the 2012 convention. "Allowing Cruz to speak when the Trump camp knew what he'd say was a sin of commission."

By allowing Cruz to speak without conditions, the Trump campaign permitted him to lay bare the divisions that still rend the party (both among movement conservatives and among sane establishmentarians, as Nick Confessore notes), totally overshadowing whatever message the campaign had planned for the evening and specifically vice presidential nominee Mike Pence's national speech. Oh yeah and it also calls into question the negotiating competence of someone whose main selling point is the so-called art of the deal.

Trumpites are spinning this as some sort of 4-D chess, long-game benevolence ("Donald Trump has been very magnanimous in his outreach," Paul Manafort, the campaign chairman, told reporters this morning), a bank-shot backfiring on the traitorous Cruz. "The party is definitely more unified," Manafort said, adding that some Cruz delegates "disagreed with what Ted did." The campaign's message hasn't been disrupted at all, he claimed placidly. (He was apparently not so placid Wednesday night when, backstage, he asked Newt Gingrich to extemporize a rebuttal to Cruz.)

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It's shades of "Return of the Jedi," where Emperor Palpatine declares that "Everything that has transpired has done so according to my design" – shortly before his apprentice turns on him and his Death Star explodes. I tend to agree with what Talking Points Memo's Josh Marshall has dubbed Trump's Razor: "Ascertain the stupidest possible scenario that can be reconciled with the available facts."

And as someone observed on Twitter last night, the one thing you can say for Cruz is that he's gotten people to stop talking about Melania Trump's plagiarism, the scandal that occupied the first half of the convention, with Trumpites like Manafort denying in the face of all rationality that the would-be first lady lifted from the incumbent. Then the campaign reversed course entirely and blamed the matter on a Trump corporate writer and family friend named Meredith McIver. Manafort, who had been steadfast in his mendacity to the point of being called on it by CNN's Chris Cuomo, was asked about that this morning as well – what did he know and when did he know it? He threw his boss's wife under the bus: "None of us knew that Miss McIver was even involved in the process," he said. "I asked Melania Trump [and] she insisted and I believed her that they were her words." When Mrs. Trump changed her story so did the campaign, he said.

As NBC News' Chuck Todd, Mark Murray and Carrie Dann write Thursday morning, the whole convention has been a series of unnecessary, unforced errors.

Here's another one: On the same day that Pence was lecturing that "history teaches us that weakness arouses evil," and declaring in no uncertain terms that "Donald Trump will ... stand with our allies" – and in the same week that New Jersey Gov. Chris Christie charged Hillary Clinton with a "dangerous lack of judgment" for "strengthen[ing] an adversary led by a dictator who dreams of reassembling the old Soviet empire" – Trump floated the idea of the U.S. not living up to its NATO treaty obligations in the face of that same adversary, led by that same dictator who dreams of reassembling the old Soviet empire.

Trump was asked by The New York Times' David Sanger and Maggie Haberman whether the U.S. would defend NATO's Baltic members if Vladimir Putin's Russia attacks. "If they fulfill their obligations to us," Trump said, "the answer is yes." The remarks, as Politico understated in a subsequent headline, "set off a freakout."

And for good reason: Mutual self-defense is foundational part of the alliance and there's no surer way to upset allies than to call that agreement into question. And as a practical political matter, one of the few themes that has come through clearly this week – aside from the GOP's desire to lock up Hillary Clinton – is the campaign's determination to scare the bejesus out of voters in the hopes of driving them to the strongman Trump. But raising once again issues of whether Trump has the judgment to handle foreign policy only undercuts that.