As usual in Washington, big news — that Attorney General Jeff Sessions twice met with the Russian ambassador during the presidential campaign and didn't disclose it during his confirmation hearings — is drawing lots of partisan finger pointing. And, as usual, the reality on who did what wrong is muddled.

As Democrats call for Sessions to a) recuse himself from an ongoing FBI probe into Trump campaign associates' ties with Russia and/or b) resign completely, Sen. Claire McCaskill (D-Mo.) offered this up as evidence for why Sessions was in the wrong:

But Republicans eager to unseat McCaskill in 2018 were quick to point out that she, herself, had met with the Russian ambassador to the United States — twice:

McCaskill's response: It wasn't in a one-on-one session. And, senators don't just meet up with ambassadors, especially ambassadors for countries that have tense relations with the United States, she said.

Actually, they do. Or at least they should be able to, said Anthony Cordesman, a foreign policy expert at the Center for Strategic and International Studies. Go to any dinner and social event in Washington in high-level foreign policy circles, and you'll probably see an ambassador talking to a lawmaker or top government staffer, Cordesman said. “It's just part of the standard pattern of social interaction.”

Sen. Ted Cruz (R-Tex.) said as much in comments to reporters:

On the flip side, The Washington Post's national security team that broke the story about Sessions's meetings with the ambassador couldn't find a single example of another senator doing the same in 2016.

Cordesman wasn't quite sure why politicians stayed so far away from Russia's top government official in the United States. Interactions between U.S. lawmakers and foreign officials are healthy for foreign policy, Cordesman said. “It isn't a matter of only talking to people you like,” he explained. “International relations would be, should we say, even worse if you refused to have dialogue with people who were hostile.”

During the Cold War, he said, anyone in the U.S. government seized an opportunity to have a conversation with Russians or Eastern Europeans. That's how hostilities get resolved peacefully.

So Sessions or McCaskill or any other lawmaker meeting (or not meeting) with the Russian ambassador isn't really that big of a deal. What is or could be a big deal is the unknown: What was the context of those meetings, and, more importantly, why didn't Sessions disclose them during two days of confirmation hearings in the Senate in January?

In a press conference Wednesday, Sessions said in a September meeting with Russian Ambassador Sergey Kislyak, the two talked about "terrorism. ... Somehow the subject of Ukraine came up; I had the Ukrainain ambassador in my office the day before, and to listen to him, Russia had done nothing that was wrong. ... It got to be a little testy at that point," Sessions recalled.

What's pertinent to Sessions's Russian conversation is that the FBI, which comes under Sessions's leadership, is investigating possible connections between Russia and some of Trump's campaign allies. Under pressure from Democrats and a growing number of Republicans, Sessions announced he'd recuse himself from any investigation involving the 2016 presidential campaign. Sessions was an early and prominent supporter of Trump's campaign.

Other than national security implications, Cordesman said, he can't think of any reason Sessions would keep mum about his contact with Russia's ambassador. (And in that case, he'd legally have to disclose the meetings privately to top committee members.)

So, Sessions meeting with the Russian ambassador isn't that unusual. But not disclosing those meetings while under oath could be a big problem for him.

That outstanding question should be our focus, Cordesman said, not that the meetings took place. The latter is a distraction and potentially even degrading to foreign policy. “That opens up the rather dismal prospect of virtually any kind of dialogue between members of Congress and foreign officials being looked down on,” he warned.

In short: Tsk-tsking meetings between foreign and U.S. officials would be a significant change in the way foreign policy is conducted now.