In the weeks and months before President Biden’s politically devastating performance on the debate stage in Atlanta, several current and former officials and others who encountered him behind closed doors noticed that he increasingly appeared confused or listless, or would lose the thread of conversations.

拜登总统在亚特兰大辩论舞台上的表现产生了灾难性的政治影响，而在那之前的几周乃至几个月里，多名现任和前任官员以及其他与他私下接触的人都曾注意到，他越来越显得困惑或倦怠，或者在谈话中跑题。

Like many people his age, Mr. Biden, 81, has long experienced instances in which he mangled a sentence, forgot a name or mixed up a few facts, even though he could be sharp and engaged most of the time. But in interviews, people in the room with him more recently said that the lapses seemed to be growing more frequent, more pronounced and more worrisome.

和许多同龄人一样，81岁的拜登早就出现过这样的情况：说错话、忘记名字、混淆一些事实，尽管他在大多数时候都能保持敏锐和专注。但在采访中，最近曾与他同处一室的人说，这样的失误似乎变得越来越频繁、越来越明显，也越来越令人担忧。

The uncomfortable occurrences were not predictable, but seemed more likely when he was in a large crowd or tired after a particularly bruising schedule. In the 23 days leading up to the debate against former President Donald J. Trump, Mr. Biden jetted across the Atlantic Ocean twice for meetings with foreign leaders and then flew from Italy to California for a splashy fund-raiser, maintaining a grueling pace that exhausted even much younger aides.

这种令人不适的情况无法预测，但似乎更有可能发生在他置身人群，或在经历了特别劳累的日程安排后感到疲惫之时。在与前总统特朗普辩论之前的23天里，拜登两次飞越大西洋，与外国领导人会面，然后从意大利飞往加州，参加盛大的筹款活动，他保持着高强度的工作节奏，连年轻得多的助手都疲惫不堪。

Mr. Biden was drained enough from the back-to-back trips to Europe that his team cut his planned debate preparation by two days so he could rest at his house in Rehoboth Beach, Del., before joining advisers at Camp David for rehearsals. The preparations, which took place over six days, never started before 11 a.m. and Mr. Biden was given time for an afternoon nap each day, according to a person familiar with the process.

连续前往欧洲的行程给他造成的消耗，促使他的团队将原定的辩论准备时间缩短了两天，让他可以在特拉华州里霍伯斯比奇的家中休息，然后再与顾问们一起到戴维营进行排练。据知情人士透露，准备工作持续了六天，都在上午11点之后开始，拜登每天都有午睡的时间。

Andrew Bates, a White House spokesman, said on Tuesday that “the president was working well before” the 11 a.m. start time each day, after exercising. Still, at a fund-raiser on Tuesday evening, Mr. Biden blamed fatigue for his debate performance. “I wasn’t very smart,” he said. “I decided to travel around the world a couple times, I don’t know how many time zones.” He added: “I didn’t listen to my staff, and I came back and I fell asleep on the stage.”

白宫发言人安德鲁·贝茨周二表示，总统每天先做锻炼，然后在每天上午11点之前开始做准备工作，“状态很好。”不过，在周二晚上的一个筹款活动上，拜登将自己在辩论中的表现归咎于疲劳。“我之前不是很明智，”他说。“我满世界跑了好几次，不知道跨越了多少时区。”他还说：“我没有听工作人员的话，我回来以后在台上睡着了。”

The recent moments of disorientation generated concern among advisers and allies alike. He seemed confused at points during a D-Day anniversary ceremony in France on June 6. The next day, he misstated the purpose of a new tranche of military aid to Ukraine when meeting with its president.

拜登最近的迷茫时刻引起了顾问和盟友的担忧。6月6日，在法国举行的诺曼底登陆周年纪念仪式上，他显得有些困惑。翌日，在与乌克兰总统会面时，他错误地陈述了向乌克兰提供新一轮军事援助的目的。

On June 10, he appeared to freeze up at an early celebration of the Juneteenth holiday. On June 18, his soft-spoken tone and brief struggle to summon the name of his homeland security secretary at an immigration event unnerved some of his allies at the event, who traded alarmed looks and later described themselves as “shaken up,” as one put it. Mr. Biden recovered, and named Alejandro N. Mayorkas.

6月10日，在提前举行的解放黑奴纪念日庆祝活动上，他似乎愣住了。6月18日，在一次移民活动上，他那轻声细语的语调，以及一度叫不出国土安全部部长的名字，让在场的一些盟友面面相觑，有人后来说，他们“被吓到了”。后来拜登醒过神来，叫出了亚历杭德罗·N·马约卡斯的名字。

He is certainly not that way all the time. In the days since the debate debacle, aides and others who encountered him, including foreign officials, described him as being in good shape — alert, coherent and capable, engaged in complicated and important discussions and managing volatile crises. They cited example after example in cases where critical national security issues were on the line.

当然，他不是一直如此。辩论失败后的几天里，他的助手和其他接触过他的人，包括外国官员，都说他状态良好——机警、条理清晰、干练，能参与复杂重要的讨论，并能处理动荡的危机。他们举了一个又一个事关国家安全重大问题的例子。

Aides present in the Situation Room the night that Iran hurled a barrage of missiles and drones at Israel portrayed a president in commanding form, lecturing Prime Minister Benjamin Netanyahu by phone to avoid a retaliatory escalation that would have inflamed the Middle East. “Let me be crystal clear,” Mr. Biden said. “If you launch a big attack on Iran, you’re on your own.”

战情室的助手们描述，伊朗向以色列发射大量导弹和无人机当晚，总统指挥若定，他在电话中告诫内塔尼亚胡总理，要他避免可能激怒中东的报复性升级。“让我把话说清楚，”拜登说。“如果你对伊朗发动大规模攻击，你就只能靠自己了。”

Mr. Netanyahu pushed back hard, citing the need to respond in kind to deter future attacks. “You do this,” Mr. Biden said forcefully, “and I’m out.” Ultimately, the aides noted, Mr. Netanyahu scaled back his response.

内塔尼亚胡极力回击，声称有必要以牙还牙，以阻止未来的袭击。“你要是这么做，”拜登强硬地说，“那我就退出。”助手们指出，内塔尼亚胡最终缩减了回应的规模。

This account is based on interviews with current and former White House aides, political advisers, administration officials, foreign diplomats, domestic allies and financial donors who saw Mr. Biden in the last few weeks, sometimes just briefly, sometimes for more extended periods. In most cases, they spoke on condition of anonymity because of the delicacy of the matter.

本报道基于对现任和前任白宫助手、政治顾问、政府官员、外国外交官、国内盟友和捐助者的采访，这些人在过去几周见过拜登，有的是短暂见面，有的时间更长。在大多数情况下，由于涉及敏感事况，他们都要求匿名。

White House officials have said the president is in excellent shape and that his debate performance, while disappointing, was an aberration. Kevin C. O’Connor, the White House physician, said as recently as February that despite minor ailments like sleep apnea and peripheral neuropathy in his feet, the president was “fit for duty.” He said tests had turned up “no findings which would be consistent with” Parkinson’s disease. The White House has declined to make Dr. O’Connor available for questions and did not respond to detailed health questions from The New York Times earlier this year.

白宫官员说，总统的状态非常好，他在辩论中的表现虽然令人失望，但这只是反常现象。白宫医生凯文·奥康纳今年2月还表示，尽管总统有睡眠呼吸暂停和足部周围神经病变等小病，但他“具备履职能力”。他说，检查没有发现与帕金森症相符的结果。白宫拒绝让奥康纳回答问题，也没有回应今年早些时候《纽约时报》就他的健康状况提出的详尽问题。

Responding to questions from The New York Times, Mr. Bates, the White House spokesman, said Tuesday that Dr. O’Connor had found no reason to re-evaluate Mr. Biden for Parkinson’s disease and that he showed no signs of Parkinson’s and had never taken Levodopa or other drugs for that condition.

周二，在回答《纽约时报》的问题时，白宫发言人贝茨表示，奥康纳医生没有发现任何理由，对拜登是否患有帕金森症进行重新评估，他没有帕金森症的表现，也从未服用左旋多巴或其他治疗该疾病的药物。

Aides to Mr. Biden responded to questions for this story by asking several senior advisers to describe their interactions with Mr. Biden.

拜登的助手在回答本文的问题时，请几位高级顾问描述了他们与拜登的互动。

“He’s inquisitive. Focused. He remembers. He’s sharp,” said Neera Tanden, the president’s domestic policy adviser. In briefings, she said, “he will ask you a tough question and he will say, ‘How does this relate to an average person?’ And if you haven’t thought of that in that time, you have to come back to him.”

“他显得好奇。专注。他记忆清晰，还很敏锐，”总统的国内政策顾问尼拉·坦登说。在简报会上，她说，“他会问你一个棘手的问题，他会说，‘这和普通人有什么关系？’如果你当时没想出来，你必须事后回去找他。”

Elizabeth Sherwood-Randall, the president’s homeland security adviser, recounted a June 17 terrorism briefing for Mr. Biden in the Situation Room in which he “digested an immense amount of information” and asked questions that were “probing and insightful.” She acknowledged that Mr. Biden’s debate performance had been different. “It doesn’t reflect the experience I have with him on a daily basis,” she said.

总统的国土安全顾问伊丽莎白·舍伍德-兰德尔回忆6月17日在战情室为拜登做反恐简报时的情况，他在会上“消化了大量信息”，提出了“深入而有见地”的问题。她承认，拜登在辩论中的表现有所不同。“这并不能反映我每天和他在一起时的情况，”她说。

But by many accounts, as evidenced by video footage, observation and interviews, Mr. Biden is not the same today as he was even when he took office 3½ years ago. The White House regularly releases corrected transcripts of his remarks, in which he frequently mixes up places, people or dates. The administration did so in the days after the debate, when Mr. Biden mixed up the countries of France and Italy when talking about war veterans at an East Hampton fund-raiser.

但很多人都说，从视频、观察和采访等许多方面来看，如今的拜登与他三年半前上任时也不一样了。白宫定期发布的拜登讲话稿是经过更正的，在这些讲话中，他经常混淆地点、人物或日期。在辩论结束后的几天里，拜登在东汉普顿的一个筹款活动上谈到退伍军人时，把法国和意大利这两个国家搞混了。

Last week’s debate prompted some around him to express concern that the decline had accelerated lately. Several advisers and current and former administration officials who see Mr. Biden regularly but not every day or week said they were stunned by his debate performance because it was the worst they had ever seen him.

上周的辩论促使他身边的一些人表达了担忧，认为他最近的下滑趋势有所加速。几位经常与拜登见面，但不是每天或每周都见的顾问，以及现任和前任政府官员说，拜登在辩论中的表现让他们感到震惊，因为这是他们印象中拜登表现最差的一次。

“You don’t have to be sitting in an Oval Office meeting with Joe Biden to recognize there’s been a slowdown in the past two years. There’s a visible difference,” said Douglas Brinkley, a presidential historian. “I’ve been amazed on one hand,” said Mr. Brinkley, who has not seen the president in person in a year. “The president can zip around the country like he does. But the White House may only be showing the Biden they want us to see.”

“你不必坐在椭圆形办公室与乔·拜登会面，就能意识到过去两年里他变得迟缓，有了明显的不同，”总统历史学家道格拉斯·布林克利说。“一方面，我很惊讶，”布林克利说，他已经有一年时间没有见过总统本人了。“总统可以像那样在全国各地穿梭。但白宫可能只是向我们展示了他们希望我们看到的拜登。”

Mr. Trump, 78, has also shown signs of slipping over the years since he was first elected to the White House. He often confuses names and details and makes statements that are incoherent. He maintains a lighter public schedule than Mr. Biden, does not exercise and repeatedly appeared to fall asleep in the middle of his recent hush money trial. His campaign has released only a three-paragraph health summary. Voters have expressed concern about his age as well, but not to the same degree as Mr. Biden’s.

自从首次入主白宫以来，78岁的特朗普这些年来也出现了走下坡路的迹象。他经常把名字和细节搞混，语无伦次。他的公共活动安排比拜登要少，也不锻炼，在最近的封口费审判中，他似乎多次睡着。他的竞选团队发布了一份只有三段的健康状况概要。选民们也表达了对他年龄的担忧，但程度不及拜登。

Mr. Trump has seized on Mr. Biden’s debate performance and called his own often confusing and fact-free appearance that night the “greatest debate performance” in the history of presidential campaigns.

特朗普抓住时机攻击拜登在辩论中的表现，还说他自己当晚经常令人困惑、缺乏事实依据的表现是总统竞选史上“最伟大的辩论”。

The picture that emerges from recent interviews about Mr. Biden is one of a president under stress — hardly unusual — as he tried to juggle nervous international partners, a recalcitrant ally whose continued war against Hamas was creating yet another threat to a second term and a family crisis with his own son, who was convicted of criminal charges that could send him to prison.

从最近对拜登的采访中可以看出，他是一位压力很大的总统——这并不罕见——他试图在紧张的国际合作伙��、顽固不化的盟友（其对哈马斯的持续战争正在对他的第二个任期造成又一个威胁）之间周旋，他还出现了家庭危机，他的儿子被判犯有刑事指控，可能会被送进监狱。

By necessity, it is an incomplete picture. As Mr. Biden has aged, the White House has limited his encounters with reporters. While he frequently stops for a couple minutes to answer a question or two, as of Sunday, Mr. Biden had granted fewer interviews than any president of the modern era and fewer news conferences than any president since Ronald Reagan, according to statistics compiled by Martha Kumar, a longtime scholar of presidential communication.

当然，这是一幅不完整的画面。随着拜登年龄的增长，白宫限制了他与记者的接触。长期研究总统沟通的学者玛莎·库马尔整理的统计数据显示，尽管拜登经常停下来几分钟回答一两个问题，但截至周日，他接受采访的次数比当代任何一位总统都少，举行新闻发布会的次数也比罗纳德·里根以来的任何一位总统都少。

On the occasions that Mr. Biden has chosen to speak with reporters on short notice, it has not always gone well. In February, he angrily hit back against a special counsel’s report on his handling of classified documents, in which the special counsel, Robert K. Hur, characterized the president as a “well-meaning, elderly man with a poor memory.” The furious president defended himself and his memory to reporters but referred to President Abdel Fattah el-Sisi of Egypt as the “president of Mexico” in the process. On Monday, House Republicans sued the Biden administration in an attempt to procure audio of Mr. Biden’s interviews with Mr. Hur.

在拜登临时起意要见记者的时候，情况也并不总是顺利。今年2月，他对特别检察官关于他处理机密文件的报告大为光火，在报告中，特别检察官罗伯特·赫尔形容拜登是“善意的、记性不好的老人家”。火冒三丈的总统冲着记者为自己和记忆力辩护，但在回答问题的时候却把埃及总统阿卜杜勒-法塔赫·塞西称为“墨西哥总统”。周一，众议院共和党人要求拜登政府提供他与赫尔的谈话录音。

But those 23 days before Mr. Biden met Mr. Trump on the television stage in Atlanta may be viewed by historians as the most critical three weeks in a consequential presidency, as the president faced an opponent he not only loathed, but viewed as an existential threat to American democracy. Were the wandering, inconclusive thoughts broadcast live to more than 50 million viewers just a bad night, a product of the exhausting month, or something larger? Had he not been crisscrossing the globe so frequently — including leaving Italy for a trip spanning nine time zones to a fund-raiser in Los Angeles — would it have made a difference?

但历史学家可能会认为，拜登在亚特兰大的电视舞台上与特朗普交锋前的23天，是他总统任期内最关键的三周，因为拜登面对的对手不仅是他讨厌的人，而且还被视为美国民主的生存威胁。向超过5000万观众直播的这番东扯西拉、没有结论的讲话，究竟只是一个糟糕的夜晚，是令人筋疲力尽的一个月的结果，还是什么更大的原因所致？如果他没有如此频繁地在全球各地奔波，包括离开意大利后，跨越九个时区前往洛杉矶参加一个筹款活动，情况会有所不同吗？

Mr. Biden’s trips to Europe were marked by moments of sharpness in important meetings — including a complex session on diverting income from Russian assets to aid Ukraine — mixed with occasional blank-stared confusion, according to people who met with him. At some points, he seemed perfectly on top of his game, at others a little lost.

据与拜登会过面的人士透露，在访欧期间，他有在重要会议上锋芒毕露的时刻，包括一场关于将俄罗斯资产收入用于援助乌克兰的复杂会议，也有偶尔出现的茫然不知所措的时刻。有时候，他看起来完全游刃有余，有时候又显得迷失。

In Normandy, he met former soldiers brought to France by a veterans’ group. One American who attended said Mr. Biden at times seemed disoriented. During the later ceremony, the president turned away from the U.S. flag when “Taps” was played instead of facing it, possibly to not turn his back to the veterans. Jill Biden, President Emmanuel Macron of France and Mr. Macron’s wife then followed suit.

在诺曼底，他会见了一群由一个退伍军人组织带到法国的老兵。据一名参与了会面的美国人说，拜登有时看上去不知道自己身在何处。在随后的仪式上，当军乐奏响时，总统没有面对美国国旗，而是转过身去，他这么做也可能是为了不想背对退伍军人显得失礼。随后，吉尔·拜登、法国总统马克龙夫妇也纷纷效仿。

There was an awkward moment when Mr. Macron made sure the president got safely down the ramp, then came back up to shake all the veterans’ hands. Mr. Biden had been expected to stay for the handshakes.

后来还出现了一个让人尴尬的时刻，马克龙先确保拜登安全地走下坡道，而后回来跟所有的老兵一一握手。而人们原本以为拜登也会留下握手。

During a meeting the next day with President Volodymyr Zelensky of Ukraine, Mr. Biden spoke so softly it was almost impossible to hear and said a new burst of aid was meant to reconstruct the country’s electric grid when it was not.

第二天，在与乌克兰总统泽连斯基的会晤中，拜登说话的声音小到几乎听不见，他说新一轮援助旨在重建该国的电网，而事实并非如此。

But when it came time for the president’s own speech on D-Day, he delivered it forcefully and clearly, gathering momentum and ending on a vigorous note. It was a reminder that, much like during the State of the Union address earlier in the year, he often rises to big occasions and once he gets the rhythm of a speech, adrenaline appears to kick in.

After several days in France, Mr. Biden flew home briefly and dealt with the family crisis of his son’s conviction. He hosted an early concert marking the Juneteenth holiday where he was spotted standing stiffly during a musical performance. One person who sat close to the president said that he had a “dazed and confused” expression during much of the event. This person said Mr. Biden had shown a “sharp decline” since a meeting only weeks earlier.

在法国呆了几天后，拜登短暂地飞回美国，处理儿子被定罪后的家庭危机。他提前举办了纪念六月节假期的音乐会，有人看到他在音乐表演的时候僵硬地站着。一位坐在总统身边的人说，在活动的大部分时间里，他的表情都显得“茫然和困惑”。这位知情人士说，自几周前的一次会议以来，拜登表现出“剧烈的退化”。

After just a couple days at home, Mr. Biden turned around and flew back to Europe, this time to Italy for a summit of the Group of 7 leaders. Throughout the meetings, the pattern was the same, according to senior officials who attended.

在国内呆了几天后，拜登又飞回欧洲，这次是去意大利参加七国集团领导人峰会。据与会的高级官员说，在整个会议期间，他的表现和之前是一样的。

Two administration officials who traveled with Mr. Biden to Italy said it is common for leaders to be guided to the day’s events. They said the hotel where the Group of 7 summit was taking place was a warren of confusing corridors filled with 25 world leaders and their security details. But they said Mr. Biden was articulate and sharp through hours of meetings.

陪同拜登前往意大利的两名政府官员说，领导人在引导下参加当日活动是正常的。他们说，举行七国集团峰会的酒店里走廊四通八达，让人犯晕，而且里面挤满了25位世界领导人和他们的安保人员。但据着这两名官员表示，在几个小时的会议中，拜登口齿清晰、言辞犀利。

Asked if one could imagine putting Mr. Biden into the same room with President Vladimir V. Putin of Russia today, a former U.S. official who had helped prepare for the trip went silent for a while, then said, “I just don’t know.” A former senior European official answered the same question by saying flatly, “No.”

当被问及是否可以想象今天让拜登与俄罗斯总统普京共处一室时，一个之前帮助准备此次访问的前美国官员沉默了一会儿，然后说：“我不知道。”一名前欧洲高级官员则干脆地回答说，“无法想象”。

Some White House officials adamantly rejected the suggestion of a president not up to handling tough foreign counterparts and told the story of the night Iran attacked Israel in April. Mr. Biden and his top national security officials were in the Situation Room for hours, bracing for the attack, which came around midnight. Biden was updated in real time as the forces he ordered into the region began shooting down Iranian missiles and drones. He peppered leaders with questions throughout the response.

一些白宫官员坚决否认了拜登不擅长跟强硬的外国元首打交道的说法，并讲述了伊朗在4月份袭击以色列那天晚上的经历。拜登和他的高级国家安全官员在战情室里呆了几个小时，为午夜时分的袭击做准备。当拜登下令进入该地区的部队开始击落伊朗的导弹和无人机后，他得到了实时更新的信息。在整个回应过程中，他不断向其他领导人提出问题。

After it was over, and almost all of the missiles and drones had been shot down, Mr. Biden called Mr. Netanyahu to persuade him not to escalate. “Take the win,” Mr. Biden told the prime minister, without reading from a script or extensive notes, according to two people in the room. In the end, Mr. Netanyahu opted for a much smaller and proportionate response that effectively ended the hostilities.

军事行动结束后，几乎所有的导弹和无人机都被击落，拜登打电话给内塔尼亚胡，劝说他不要将行动升级。据当时在作战室的两个人说，拜登对以色列总理说，“见好就收，”他没有照着稿子念，也没有去翻之前做的许多笔记。最后，内塔尼亚胡选择了规模小得多、更为适度的回应，有效地结束了敌对行动。

Since the debate, Mr. Biden has tried to demonstrate that his trouble articulating himself that evening was not indicative of a larger problem. He gave a robust speech at a campaign rally the next day and attended a string of fund-raisers where he hoped to reassure nervous donors.

“He gave a strong speech, he didn’t stumble or mumble or look confused in any way,” said Judith Hope, the former chair of the New York State Democratic Party, who attended a fund-raiser in East Hampton on Saturday. “He was his old Uncle Joe self.”

“他的演讲很有力，他没有口吃、口齿不清，也没有表现出困惑的样子，”前纽约州民主党主席朱迪思·霍普周六在东汉普顿参加一场筹款活动时说。“他还是那个乔大叔。”

Ms. Hope attributed the president’s debate troubles to his demanding schedule. “Are you aware of where he has been in the past seven days?” she said, raising her voice. “He continues to keep up a schedule that I could never dream of doing, that would totally defeat a younger person,” she added. “I think we need to examine our expectations.”

霍普将总统在辩论上的表现归结为密集的日程安排。“你知道他过去七天都在哪里吗？”她提高了声音说道。“他仍然保持着一个我无法想象的日程安排，年轻人都吃不消，”她补充道，“我认为我们需要看看自己的预期是否符合实际。”