Back in 2005, when I was the United States’ lead negotiator at the six-party talks on North Korea’s nuclear program, I looked at the instructions I received for my first meeting, a Chinese-hosted banquet that included a North Korean delegation. If there was any toasting (not unheard of at Chinese banquets), I was not to join in. Apparently, I was expected to sit there, without touching my glass, glowering with arms folded until everyone else had placed theirs back on the table. Later, when I visited North Korea for the first time, I was instructed not to smile at my hosts. Apparently, I was expected to offer only angry stares.

Donald Trump has obviously modified those instructions. In fact, with his unending praise of Kim Jong-un’s leadership, his clumsy, impromptu salute of one of Kim’s generals, and his endorsement of all things North Korean (especially the potential for beachfront property development), Trump has all but abandoned any pretence that the US promotes a broader set of values. But while Trump may have overshot the mark, the idea that the US delegation should sit with glasses untouched during a toast also strikes the wrong tone.

In September 1995, during the final month of the Bosnian War, the US delegation to peace negotiations, led by Assistant Secretary of State Richard Holbrooke, arrived in Belgrade for talks with Serbia’s dictator, Slobodan Milošević. According to Milošević, he could not compel the Bosnian Serbs to withdraw their heavy weapons and lift the bloody four-year siege of Sarajevo. He asked Holbrooke to meet with the Bosnian Serb leaders, Radovan Karadžić and Ratko Mladić, both of whom were later convicted of committing war crimes. Holbrooke asked where they were. ‘Over there in that villa’, Milošević replied. ‘Can I call for them?’

Holbrooke hastily brought our delegation together for a quick parley. ‘Should we meet them?’ he asked me. ‘And if we do, should I shake their hands?’ Thinking about the hundreds of thousands of Sarajevans—the many who had been murdered and those facing starvation as a result of the continuing siege—I replied, ‘Shake their hands and let’s get this over with and go home.’ We did. The siege of Sarajevo was lifted the next day.

Whether shaking a hand helps or not, negotiating while shaking a fist has little record of success. During this year’s Pyeongchang Winter Olympics, Vice President Mike Pence was scheduled to meet with the North Korean delegation. Perhaps to cover his back at home, Pence delivered what were then the usual tough-sounding talking points before the meeting. The North Koreans promptly cancelled, as if to ask, What would be the point?

During the period I dealt with the six-party talks, I avoided adding my voice to the anti-North Korean invective. I knew that soon—often every other week—I would have to meet them again, and while a display of moxie might help me in Washington, it would not help at the tip of the spear, where it was my job to negotiate away the North Koreans’ nuclear ambitions. There is a big difference between talking tough on television talk shows and sitting across from the North Koreans. Direct diplomacy is a serious means to a serious end. Posturing from a distance is not part of it.

Sometimes body language is hard to get right. As US ambassador to Iraq, the instructions I received from Washington rarely came with any commensurate sense of responsibility for the outcome. I was told that my job included helping the Iraqi opposition rid themselves of then-Prime Minister Nuri al-Maliki. US officials revelled in their amped-up toughness in Washington meeting rooms, like high school athletes banging on the lockers before a big game. But when they actually came out on the field and met with Maliki, they gave him no reason to believe they wanted anything but the best for him.

I would sit in such meetings watching Maliki glance over at me, wondering why I had previously warned him of diminishing US government patience with his autocratic rule and dire consequences. Meanwhile, the visitors from Washington made points that were so subtle and nuanced that Maliki would have needed a decoding device to comprehend their real meaning.

Any diplomat must be purposeful in a negotiation on behalf of his or her country, which means being clear-eyed about the desired outcome and the best way to achieve it. In Singapore, the issue was the North Korean nuclear weapons program. Nothing else really mattered.

Time will tell whether the North Koreans reciprocate Trump’s professed affection for them. Kim gave away little, and was probably stunned when, for the first time ever, a US president accepted at face value North Korea’s supposed anxiety about US joint military exercises with South Korea (which the North Koreans know to be defensive in purpose). That was too large a concession, and, one way or another, it will have to be taken back. More broadly, a framework for peace and security that includes all the directly affected parties—South Korea, Japan, Russia and China—will need to be designed.

Similarly, North Korea’s human rights record, one of the world’s worst, will have to be taken up in the future—perhaps, as I signalled during the six-party talks, as a component of eventual diplomatic relations. But, for now, the North Korean nuclear program must be at the top of any negotiating agenda.

Whether Trump’s approach actually works with North Korea will depend on the diplomacy that follows the Singapore summit. Over to you, Secretary of State Mike Pompeo.