For days, President Trump insisted that he would accept nothing less than full ownership of Greenland. He dismissed concerns that his demands were risking the disintegration of the primary Western military alliance, deriding it as impotent anyway without the United States. And he threatened economic war on anyone who tried to stop him.

幾日來，川普總統一直堅稱，完全擁有格陵蘭是最起碼的條件。人們擔心這一主張可能導致西方主要軍事聯盟的解體，對此他表達了不屑，嘲笑這個聯盟如果沒有美國本來也就是個空架子。他還威脅對任何試圖阻止他的人發動經濟戰。

Then he took it all back.

然後他就收回了所有這些言論。

On Wednesday, Mr. Trump’s dizzying approach to foreign policy was on full display in the thin air of the Swiss Alps. Just hours after using a keynote speech in Davos, Switzerland, to insult European leaders and demand control of Greenland, he declared himself satisfied with a framework of a deal on the Danish territory that was so vague he could not say whether he would actually own the island.

週三，在瑞士阿爾卑斯山稀薄的空氣中，川普充分展現了他那令人眩暈的外交風格。他在達佛斯世界經濟論壇的主旨演講中侮辱歐洲領導人並要求控制格陵蘭島，僅數小時後，他就宣布就這片丹麥領土達成了一個如此模糊的協議框架，以至於他無法明確自己是否真的會擁有該島。

His threats of tariffs against Greenland’s defenders quickly vanished. After questioning the value of NATO, he declared that its leader, Mark Rutte — with whom he negotiated over Greenland — was “doing a fantastic job.”

他對格陵蘭島捍衛者施加關稅的威脅迅速消失。在質疑北約價值後，他宣稱北約領導人馬克·呂特——與他就格陵蘭島進行談判的人——「幹得非常出色」。

“We’re getting everything we want,” Mr. Trump said in an interview with Fox Business from Davos on Thursday, before adding only a couple breaths later that the deal was still being negotiated.

「我們正在得到我們想要的一切，」川普週四在達佛斯接受福克斯商業頻道採訪時說，轉眼他又補充說協議仍在談判中。

The volatility in Mr. Trump’s approach to foreign policy is a sign of just how emboldened he feels a year into his second term. He transformed a forum that epitomizes the Western establishment and the rules-based order it created into a stage for his unconstrained power to overturn the values it stands for, if he so chooses.

從川普在處理外交問題上的反覆無常，可以看到他在第二任期一年後感到更加有恃無恐。他將這個象徵西方建制派及其所創造的基於規則秩序的論壇轉變為展示他不受約束的權力的舞台，如果他願意，就可以顛覆其所代表的價值觀。

He has long spoken of his unpredictability as one of his strengths, saying there is a method to the madness that helps him win deals in ways that the tired routines of traditional diplomacy do not. His allies point to Gaza, Venezuela, Iran, Panama and other places — and to trade concessions by nations around the globe — as evidence that his techniques pay dividends.

他長期以來將自己的不可預測性視為優勢之一，稱這是一種手法，能以老一套的傳統外交無法做到的方式贏得交易。他的盟友說，加薩、委內瑞拉、伊朗、巴拿馬等地——以及全球各國在貿易上的讓步——可以證明他這一手法的成效。

But his whipsaw approach has also led Europeans to question the reliability of the United States and whether the world has moved on from post-World War II structures.

但他的反覆無常也讓歐洲人質疑美國的可靠性，以及世界是否已拋棄二戰後的架構。

“Everybody’s trying to figure out, you know, what is it that — what does the president really want?” Senator Lisa Murkowski, Republican of Alaska, said when asked what European leaders had wanted to know from her in Davos. “What’s his intentions with Greenland; what are his intentions with NATO?”

「每個人都在試圖弄清楚的，就是總統真正想要什麼？」在被問及歐洲領導人在達佛斯想從她那裡了解什麼時，阿拉斯加州共和黨參議員麗莎·穆爾科斯基說。「他對格陵蘭島的意圖是什麼；他對北約的意圖是什麼？」

His sudden announcement on Wednesday that he would not follow through on a threat to impose tariffs on countries that opposed his plans to take over Greenland sent heads spinning. But it also felt familiar — he has canceled, suspended or reduced tariffs against dozens of countries, in many cases after winning concessions that were less than he had demanded.

他週三突然宣布，之前向反對其接管格陵蘭島計劃的國家加徵關稅的威脅不會實施，這讓人們大感困惑，但同時也覺得似曾相識——他已取消、暫停或降低對數十個國家的關稅，而且很多時候他得到的讓步並沒有達到他的最低要求。

Mr. Trump’s aides often argue that his use of tariffs is an effective negotiating tactic. After his meeting with Mr. Rutte, the secretary general of NATO, on Wednesday night, Mr. Trump celebrated the framework on Greenland “as a good deal for everybody.”

川普的助手經常辯稱，他使用關稅是一種有效的談判策略。週三晚與北約秘書長呂特會晤後，川普讚美格陵蘭島的框架「對每個人都是好交易」。

But his announcement also followed a pattern in which he claims victory in a negotiation before major details have been settled. When asked if the framework would include U.S. ownership of Greenland, Mr. Trump paused. “It’s a long-term deal,” he added, without providing specifics.

但他的宣布也遵循一種模式：在主要細節尚未敲定前就宣稱談判勝利。當被問及框架是否包括美國擁有格陵蘭島時，川普停頓了一下。「這是一個長期協議，」他補充說，沒有提供具體細節。

A senior Danish official, who spoke on condition of anonymity to discuss sensitive diplomacy, said, “There have been no direct discussions between Denmark and the U.S. about the possibility of granting the U.S. sovereign parcels of land.”

一位因涉敏感外交而要求匿名的丹麥高級官員表示：「丹麥和美國之間尚未就授予美國主權土地的可能性進行直接討論。」

With Mr. Trump riding high after the dramatic U.S. military raid this month that seized Nicolás Maduro, the Venezuelan leader, many Davos attendees knew there could be sparks from the president’s speech on Wednesday.

在本月美國軍隊戲劇性突襲抓捕委內瑞拉領導人馬杜羅後，川普風頭正勁，許多達佛斯與會者知道週三總統的演講可能引起轟動。

The vague threats and insults that followed were still on many minds on Thursday.

川普隨後發出的含糊威脅與侮辱性言論到了週四仍縈繞在許多人腦海。

Friedrich Merz, the German chancellor, stepped onto the same stage where Mr. Trump had a day before questioned the value of NATO and had framed Greenland as a debt that needed to be paid to the United States.

在川普質疑北約價值並將格陵蘭島稱為拖欠美國的債務一天後，德國總理弗里德裡希·默茨登上了同一個舞台。

Mr. Merz used his speech to note how the United States was “radically reshaping its foreign and security policy.” He pointed to the dangers of the Trump administration’s might-makes-right approach, unburdened by many postwar Western values.

默茨在演講中指出，美國正在「徹底重塑其外交和安全政策」。他指出了川普政府「強權即公理」方式的危險，這種方式不再受許多戰後西方價值觀的制約。

“The United States’ global pole position is being challenged,” Mr. Merz said. “We have entered a time of great-power politics. As we forge ahead, we must never forget one thing: A world where only power counts is a dangerous place — first for small states, then for the middle powers and, ultimately, for the great ones.”

「美國的全球頭號地位正在受到挑戰，」默茨說。「我們已進入大國政治時代。接下來，我們絕不能忘記一件事：一個只講實力的世界是危險的——首先對小國，然後對中等強國，最終對大國，都是如此。」

He then implicitly chided Mr. Trump for his demeaning treatment of European allies.

“Democracies do not have subordinates,” Mr. Merz said. “They have allies, partners and trusted friends.”

「民主國家沒有下屬，」默茨說。「它們有盟友、夥伴和值得信賴的朋友。」

The German leader’s comments echoed those of Prime Minister Mark Carney of Canada, who said on Tuesday that a world order dependent on superpowers like the United States was coming to an end. In a speech widely discussed by Davos attendees, he called the phase a “rupture.”

Mr. Trump responded by saying that Canada should be “grateful to us.”

川普回應稱，加拿大應該「感激我們」。

The president’s unpredictability largely dominated a summit that in the past had amounted to a brainstorming session among financial and political elites. Attendees rearranged their meetings in order to see Mr. Trump speak. In years past, participants had been able to show up at the main auditorium only a few minutes before keynote addresses by presidents and prime ministers and find a seat.

總統的不可預測性主導了這次峰會，過去，這裡只是金融和政治精英的頭腦風暴會議。與會者為了觀看川普的演講，需要重新安排自己的會議日程。往年，參與者只需在總統或總理主旨演講前幾分鐘抵達主禮堂就能找到座位。

This year, a full 90 minutes before the main event, hundreds of people jammed the entire ground floor of the enormous convention center.

今年，主活動開始前整整90分鐘，舉行會議中心的底層就已經擠了數百人。

“No pushing!” staff members said with increasing intensity as people shoved and maneuvered.

「不要推搡！」隨著人們推來擠去爭奪位置，工作人員的語氣越來越緊張。

The presence of the president and his delegation brought tension to a gathering that usually features like-minded businessmen. When Howard Lutnick, Mr. Trump’s commerce secretary, delivered remarks at a dinner earlier in the week, he was heckled by former Vice President Al Gore, a prominent climate activist.

總統及其代表團的出現給這個通常由志同道合的商界人士參加的聚會帶來了緊張氣氛。本週早些時候，川普的商務部長盧特尼克在晚宴上發表講話時，被著名氣候活動家、前副總統高爾喝倒彩。

“It’s no secret that I think this administration’s energy policy is insane,” Mr. Gore said in a statement. “And at the end of his speech I reacted with how I felt, and so did several others.”

「眾所周知，我認為本屆政府的能源政策是瘋狂的，」高爾在聲明中說。「在他演講結束時，我表達了我的感受，其他幾個人也是如此。」

“Thankfully, we didn’t come to Davos for Al Gore’s praise,” Mr. Lutnick said on Thursday on social media.

「謝天謝地，我們來達佛斯不是為了阿爾·高爾的讚美，」盧特尼克週四在社群媒體上說。

In Mr. Trump’s volatility, there is also the chance that those on the receiving end will emerge better than they had expected.

川普多變的特質，也可能令接收方感覺比預期的要好。

Some Europeans told current and former U.S. officials at Davos that they were leaving the event feeling better than when they had entered, after Mr. Trump lifted his imminent threat of tariffs.

一些歐洲人在達佛斯告訴現任和前任美國官員，在川普解除即將到來的關稅威脅後，他們離開峰會時感覺比抵達時更好。

But before leaving on Thursday, Mr. Trump again raised the possibility of pivoting.

但在週四離開前，川普再次提出轉變方向的可能性。

He said that European nations that had sold off U.S. bonds could face his wrath.

他說，他不會放過那些出售美國國債的歐洲國家。

“If they do, they do, but you know, if that would happen, there would be a big retaliation on our part,” Mr. Trump said. “And we have all the cards.”

「如果他們這麼做，那就做，但你知道，如果發生這種情況，我們將進行大規模報復，」川普說。「我們手裡有的是牌。」