We now know Donald Trump Jr.’s (latest) defense. “It was such a nothing,” he told shadow White House press secretary/Fox News host Sean Hannity. Then he said it again. “It was such a nothing, there was nothing to tell [my father].” And again. “It was such a nothing, I literally wouldn’t have remembered the meeting.”

Trump Jr.’s defense is worth examining closely, as it paints the way, I think, toward a broader theory of Trumpworld’s relationship with Russia — a theory that has space both for the collusion that seems likely, at this point, to have happened, and for the very real sense of persecution and confusion we’re seeing among Trump’s circle.

Let’s begin with Trump Jr.’s defense. He isn’t disputing the facts of the meeting. He has released the emails. He admits he attended. He admits Jared Kushner and Paul Manafort attended. His contention is entirely over interpretation. What looks like a big deal in retrospect was not, he says, a big deal at the time. “This was before the Russia mania,” he said, so “I don’t think my sirens went [off] or my antenna went up at this time because it wasn’t the issue that it’s been made out to be over the last nine months, 10 months."

Why did Trump Jr. go at all? Because he believed, deeply, that there was something out there that could take down Hillary Clinton — and he was hoping against hope that this Russian lawyer might have it. "I had been reading about scandals that people were probably underreporting for a long time, so maybe it was something that had to do with one of those things," he told Hannity. He wasn’t looking to collude with a foreign government to influence an American election. He was looking to expose a corrupt presidential candidate whose presidency might endanger the nation.

Is Trump Jr.’s story credible? Yes and no.

Here is what I find believable in Trump Jr.’s explanation: This wasn’t a big deal to him at the time. He did not wake up and write in his day planner “collude with semi-hostile foreign power to undermine the foundations of American democracy.” To Trump Jr., Clinton was getting away with murder — perhaps literally. If he could find information that would shed light on her nefarious activities, he would be the hero of the story, not the villain.

Part of a campaign is meeting with interest groups, elected officials, and weirdos to ferret out useful information. And Trump and his family were novices at this. They may not have understood there was a critical difference between working with the Kochs and working with the Chamber of Commerce and working with this one private investigator they knew back in New York and working with representatives of a foreign power.

So I am open to the idea that Trump Jr. is telling the truth when he says, in retrospect, this felt like nothing — one meeting out of hundreds, and not a particularly good one at that.

But here’s where his story falls apart: That doesn’t mean it was nothing.

First, Trump Jr. knew what the meeting was supposed to be. It was a “Russian government attorney” who wanted to “provide the Trump campaign with some official documents and information” as “part of Russia and its government’s support for Mr. Trump.” And even if Trump Jr. didn’t understand all the lines that crossed, Paul Manafort, the campaign manager who was copied on the email and who attended the meeting, should have. Remember the subject line of the email: “Russia - Clinton - private and confidential.”

The meeting might have been nothing, in the end. But it was supposed to be something. And the something it was supposed to be was genuinely sinister.

Second, the meeting comes in the context of a profusion of weird meetings between Russian officials and Trump staffers — meetings that the Trump staffers keep lying about. And that profusion comes in the context of an election where Russia really did hack Democratic emails and release them in ways timed to maximally embarrass Clinton, and where Donald Trump Sr. repeatedly — and at great political cost — praised Vladimir Putin and undercut the anti-Russian NATO alliance.

Here, after months of following the Trump-Russia story, is what I think is likely to prove true. Yes, there was collusion between the Trump campaign and the Russian government — probably over the hacked emails, and perhaps on other matters.

At the same time, I think Trump Jr.’s emotional reaction to all this is honest. The collusion was probably petty. A heads-up here. Some advice on when it would be most useful for hackers to release certain emails there. Some oppo exchanges, perhaps. The Trump team was working with dozens of interest groups in precisely this way at all times. If they were working with intermediaries for the Russian government, too, it probably didn’t feel like a spy novel. It felt like one more meeting in a day full of them. And maybe it was even wrapped in what seemed, to the Trump team, like legitimate foreign policy goals: Maybe this was the basis for a new era of cooperation with Russia!

It’s only in retrospect that they have come to realize that contacts and relationships they considered banal were unethical, scandalous, and perhaps criminal. And so the lying began. The denials. The cover-up. The forgotten meetings. The firing of James Comey. Now they see their actions and meetings on A1 of the New York Times and plastered on cable news and they know the facts are true even as the spin feels false. The media’s witch hunt feels genuinely unfair to them — none of this was a big deal!

But it is not unfair. The 2016 US election was infected by a crime. A foreign government stole documents belonging to one of the political parties and used them to try to change the outcome of the election. Given the razor-thin margin of Trump’s victory, they may well have succeeded. If the Trump campaign was aware of and cooperating in that effort, Russia earned favor from, and leverage over, the current presidential administration.

In all this, I keep thinking about former CIA Director John Brennan’s testimony on Russia’s role in the 2016 election. "Frequently, people who go along a treasonous path do not know they are on a treasonous path until it is too late,” he said.

Put aside the word treason, which perhaps goes too far. There is a profound insight in Brennan’s comment. It is entirely possible that the Trump campaign did something terribly, terribly wrong without realizing exactly what they were doing, or why it was so wrong. Campaigns are chaotic, they were amateurs, and when you feel the other side has every advantage, it’s easy to rationalize your actions in response. But that doesn’t excuse them.

Watch: What we know about Donald Trump Jr.'s connection to Russia