Russian President Vladimir Putin is a dictator who has used the Russian government to enrich himself and his friends. His words and promises are lies. He has waged two low-intensity wars of aggression against other nations in the last decade. He has caused massive numbers of needless civilian deaths and is implicated in political assassinations both in Russia and in the West.

It is also by now well established that Russia was behind a massive propaganda effort and an illegal hacking operation to weaken Hillary Clinton, once presumptively the next American president, during the 2016 election. To this must be added the fact that Putin skillfully played and made fools of the last two American presidents, George W. Bush and Barack Obama, who downplayed the threat he posed, trusting him and, in Obama's case, promising him "flexibility" on policy when no trust was warranted.

This week, the public has learned that Donald Trump Jr. agreed to meet a Russian lawyer linked to the Kremlin during the 2016 election. He met her because it was claimed by an intermediary that she had opposition research on Clinton, whom Trump Sr. was facing in the general election. It turned out the attorney had no dirt and instead used the opportunity to discuss adoption policy, a topic closely tied to American sanctions against Russia.

That Trump Jr. agreed to this meeting evinces a serious lack of judgment, at the very least. The email chain setting it up, which he released on Tuesday through Twitter (apparently in the belief that he should get out in front of the story), shows he had been told that the information was related to the Russian government's desire to help his father's campaign. He may not have paid close attention, but the information was given to him. He had been warned. And at least some of the others to whom he forwarded it, Paul Manafort, especially, a seasoned operative and Trump's campaign manager, should have known better, even if Trump Jr. did not.

That June 2016 meeting will now be investigated, as it should be, thoroughly. Investigators should be expected to question all involved and obtain documentary evidence for any hint that the Trump campaign encouraged or knew of crimes the Russians may have committed related to the election, specifically the crime of hacking Democrats' emails and possibly the emails of various state election officials.

Having said all that, there appears to be no evidence of an actual crime in what we know. It would be a mistake to look at the current evidence of unethical behavior through impeachment-colored glasses.

There is, however, finally evidence of collusion, or a willingness to collude, with Russia. Even if no actual work was done, high-level Trump campaign aides were willing to work with someone identified to them as operating on the Russian government's behalf. There may be more evidence coming of lies told along the way, perhaps under oath, in the form of past denials that any such communication or collusion occurred, by people in the know.

But it must also be noted, with talk of impeachment in the air, that the more robust version of the theory of collusion has not been buttressed, let alone vindicated. Sen. Tim Kaine, D-Va., looks ridiculous with his remarks that the new revelations "transition this potentially into a treason investigation." The allegation in Democratic fever swamps has been that the Trump campaign colluded with Russia in a conspiracy to subvert American democracy, not just in the sleazy hope of attaining an offered bit of dirt to use against an election opponent.

If Trump's team knowingly enlisted or helped Moscow commit the crimes of which it plausibly stands accused, we still don't have the evidence. And bad as this week's news is for the Trump White House, that distinction matters, even if it doesn't provide a justification or a defense in the court of public opinion.

Hacking is a crime. Treason is a crime. Perjury is a crime. Sleazy behavior in investigating one's election opponents is often legal. The released emails suggest but don't prove that Trump's campaign lacked an established line of communication with Moscow as of mid-June 2016, by which time Russia's illegal hacking of Democrats was already complete.

Campaigns love opposition research. They don't usually turn to foreign governments for it, nor should they. But they also don't often turn down chances to look at it. Journalists don't either, for that matter. To cite a pertinent example, whatever serious ethical questions were raised about the infamous dossier on candidate Trump, the juiciest allegations of which came from Russian officials, its compilation and publication were not described as treasonous, and it probably would not have violated campaign finance laws had its allegations been used by his opponents.

Bad as Trump Jr.'s judgment was in accepting his meeting last June, it is obvious why he saw potential in it. By the time it was offered, various reports, including a prominent one in The New York Times from before Trump was a candidate, had established that unsavory Russia-Clinton dealings had occurred in 2010, including what looked as if it might have been a trade of half a million dollars that July for an official act benefiting the Kremlin, in which Secretary Clinton had an official role, that October. So the idea that there might have been more Clinton-Russia dirt must have seemed both plausible and enticing to the younger Trump.

Yet he should never have taken the meeting, let alone harbored the illusion that any information coming to him from Moscow would have any credibility.

Trump Jr.'s meeting must be and will be investigated, now that it has come to light. And if that leads somewhere, then it leads somewhere.