The latest Washington scandal reads like a 19th century morality tale: The president met with Vladimir Putin by himself! Without his own interpreter! For an unscheduled hour! No one knows what happened! His virtue is forever in question.

Talking heads, the tittering class of modern Washington, are apoplectic. As often happens in a moment of scandal, pundits deliver their condemnation in absolutes—presidents never have one-on-one meetings!—and sprinkle them with enough “back in my days, we never did that” to fill a giant pot of borscht. Inevitably, the cycle will produce a well-respected predecessor who also sinned and we will start anew.

Of course, presidents can and do have one-on-one discussions with other world leaders; summits abound with photos of President Barack Obama pow-wowing with the likes of Dilma Rousseff, Angela Merkel and, yes, even a few chats with Vladimir Putin; a critical point in U.S.-Cuba negotiations came during a formal one-on-one meeting with Pope Francis. But of course, President Trump, a greenhorn on the global stage, should have known better than to sit down unprepared and alone with a canny adversary like Putin. His solo meeting with the Kremlin strongman, which the White House is downplaying as a short and casual exchange of pleasantries over dessert, committed several cardinal sins of diplomacy: It was unplanned, unstaffed, undocumented, unending and undisclosed. But perhaps more importantly, it made an impression while everyone at the G-20 was watching.

It’s (Not) My Party

For the moment, think of Trump as a regular person, like you, going to a party. When you walk in the door, you instantly spot that guy — the one who spits when he talks, thinks the two of you should “work together someday” and takes every awkward smile of acknowledgment as a marriage proposal. You, a full-grown adult, are usually perfectly capable of avoiding him. Except when you can’t. What do you do? What do you say? What will people think?!

And this is where the similarities between you and the president probably end: Everyone in the room wants something from him. But life as the leader of the free world is — or tries to be — a highly scripted and orchestrated endeavor, never more so than when on international travel. All of his (or her) moments have an objective, or should, despite national security adviser H.R. McMaster’s mind-boggling statement that there was no particular agenda for his boss’ first meeting with Putin. World leader face time is a limited commodity, and not taking full advantage of such engagements through careful planning is a huge missed opportunity.

A lengthy meeting without staff is a choice presidents can make in rare circumstances, but it’s a signal as much as it is a talk — I trust you, we are friends, this is so important it must be among us.

When staffing my first presidential trip as a National Security Council staffer, I was astonished to review talking points for dozens of possible discussions throughout every second of the day. Bilateral meetings were highly planned, and even seemingly casual pull-asides were often carefully negotiated and scheduled. An important bilateral meeting might involve the brainpower of half the NSC agencies, many pages of painstakingly drafted meeting objectives to hit and landmines to avoid, pep talks to push for outcomes worthy of a presidential trip, extensive protocol debates and one or two or more preparatory meetings. This may seem like overkill to experienced masters of three-dimensional chess. But a well-managed presidential trip is one in which the boss is never surprised by a mysterious request, a heretofore unknown grievance or a solo gripe session from a counterpart. An exceptional trip is one in which every engagement gets points on the board.

The lists of people joining these meetings were nearly as highly scrutinized. In prior administrations, the national security adviser personally reviewed such lists and generally accompanied the president to even the most sensitive discussions. Who flanks the president in any engagement is no accident, and when he meets alone for an extended period, it’s no accident either. These choices are signals to the world about who the president views as his top representatives, and wants to form relationships with — as well as more practical matters, such as who the president can turn to to offer technical details, or delegate a sensitive matter.

But the most important function of the folks around the table is to record what is said. The most junior person in the room, whether national security adviser or lowly diplomat, knows very well it is their highest priority to record every utterance. Such summaries are invaluable to do lists, intelligence fodder, and the foundations for negotiations of many administrations to come. Without them, senior leaders can end up in disastrous versions of he said she said; Ambassador April Glaspie’s solo discussion with Saddam Hussein before the Gulf War being a prototypical case. Meetings where one or both sides lack a note taker give the more devious of the two free reign to issue narratives sympathetic to their interests, if not outright fabrication; even the first small bilateral meeting between Trump and Putin already has resulted in conflicting accounts. That said, even in the best of circumstances, U.S. note takers can come away with different impressions.

This Isn’t ‘Nam, Man, There are Rules

Anyone would chafe at these restrictions and take the opportunity to go rogue, but it’s not hard for global leaders to see the benefit, too. Few enter their roles well-versed on all of their country’s current foreign entanglements. And while just winging it during the G-20 family photo probably wouldn't result in any world wars, an unplanned, unsupported and unannounced hourlong bull session is a risky affair. How well would you perform in a high-stakes meeting where everyone else had done their homework and you just … wandered in? Poorly, one imagines. Preparation is everything.

Even with such trappings, it’s easy for participants to walk away from a session convinced of diametrically opposite results. The matter of whether the United States committed to the then-Soviet Union to avoid eastern expansion of NATO, and whether it violated the spirit or letter of these discussions, is still under dispute, with historians and diplomats haggling over memos and detailed notes from opposing sides to this day.

But surely, you think, can’t a president kick back with his fellows for a couple hours and exchange pleasantries over chocolate mousse? Well, no. At a G-20 dinner, before the 19 other world leaders came in the room, their senior advisers almost certainly said, “Try to nail down Trump on XYZ.” Seating assignments often are proffered in advance to allow leaders to prepare their discussions. Staffers warn that so-and-so might seek a 15 minutes chat, so try to meet in the hallway so someone can join you. And sometimes, mealtime chatter is observed by “sherpas” listening in from another room.

Thus prepped for battle by an anxious staff, the wise solo head of state works through his targets, makes his points, consults his adviser outside, offers delays when confronted on emotionally charged matters and extricates himself from those over-eager for a long unsupervised chat. Teens on the birthday party circuit deftly manage such feats; elected officials can too.

Pie in Your Face

A lot of ad-libbing goes on based on the experience of the participants, often for the better. Unplanned moments, large and small, result in breaking barriers no summit memo would ever conceive; you can see this in Reagan and Gorbachev’s breakneck and breathtaking negotiations in Reykjavik, conducted on short notice, or Obama’s first handshake with Raúl Castro in South Africa. But there’s freelancing, and then there’s attempting a double black diamond during your first time on the slopes. In government, we do things very carefully for a reason. Trump might have been winging it at the G-20, but everyone else in the room meant business, Putin especially so.

And here’s the crux of why this impromptu summit was so dangerous: Trump may fancy himself a master deal-maker, but regardless of your feelings about him, his inexperience in international affairs is undeniable; Putin, by contrast, has decades of KGB training and diplomatic experience. Trump has, er, challenges in recalling his statements and commitments; Putin is known to have an incredible memory and amazing control of details. In such a conversation, every statement becomes U.S. policy, whether Trump realizes it or not. With no staff to steer or generate an American record of the discussion, even an experienced, disciplined president would struggle to control the resulting narrative. In Trump’s case, what Putin takes away from this fiasco is a parade of potential horribles, from a green light for more aggression in Ukraine to an endorsement of Russian meddling Syria. And that’s if you don’t believe the worst suspicions of why Trump would want to meet with Putin alone, without telling the public.

And that’s not the only problem with the Great Dessert Summit of 2017. Either Trump’s aides didn’t know he was going to amble across the table for a confab with the leader of America’s No. 1 geopolitical adversary, or they knew, and he ignored their advice and did it anyway. A third possibility — that they somehow thought this was a good idea — is hard to imagine. Which brings us to the next problem with the meeting: What are Trump’s G-20 counterparts to make of this? They probably observed his talk with Putin as one views a colleague embarrassing themselves at the office Christmas party: Does he not know better?

A lengthy meeting without staff is a choice presidents can make in rare circumstances, but it’s a signal as much as it is a talk — I trust you, we are friends, this is so important it must be among us. Choosing to engage in so consequential a discussion — because any hourlong discussion with Putin will have consequences — without McMaster or Secretary of State Rex Tillerson also weakens their standing publicly. And concealing, pooh-poohing and declining to own the narrative by offering no readout of the meeting makes the president appear foolish. The president’s peers sat together over coffee and watched him get taken advantage of, willingly, with a smile on his face. Not the first impression Trump might have hoped for.

Loren DeJonge Schulman is deputy director of studies and the Leon E. Panetta senior fellow at the Center for a New American Security.