"How to Win Friends and Influence People," a self-help book by Dale Carnegie, was first published in 1936. It has since sold more than 30 million copies worldwide.
A year in to his presidency, Donald Trump has shown the value of Carnegie's insights.
Never before in the field of American foreign policy have so many of the nation's friends been lost with such speed by one man.
He began his days in the White House mired in controversy through his travel ban on people from several Muslim-majority countries that instantly spread suspicion among Islam's 1.6 billion faithful that he didn't like them.
Fast-forward to the closing days of his first year in office, and he was reportedly offending an entire continent.
In between these bookend events, he has made himself toxic to some of the closest US allies and lost their support and leverage for his agenda.
Witness the recent flurry of European statements over Iranian compliance with the Obama-era nuclear deal that cut Tehran's immediate pathway to a nuclear bomb.
Every international partner that Obama helped corral to snap controls on Iran's nuclear ambitions in 2015 spoke out as Trump mulled nullifying the deal.
During his fall visit to Asia, Trump proudly proclaimed his "America First" vision. He offered nations bilateral trade deals, only to have his host of a few days -- Japanese Prime Minister Shinzo Abe -- restart the very multilateral Trans-Pacific Partnership trade agreement, without America, that Trump trashed during his first days in office.
Trump had shared burgers and played golf with Abe days earlier in Tokyo.
Carnegie's insights may not have been on Trump's mind when he and Abe strolled the golf course. Had they been, history might be written differently, and Trump might not have faced such a public put-down.
Yet the year cannot be chalked up as only losses for Trump.
Carnegie might smile about Trump's new relationships in Saudi Arabia -- although maybe not on account of Trump's political acumen.
The Saudi crown prince, Mohammed bin Salman, has cultivated a classic national leader's relationship with Trump based on mutual and national interest: Both men detest Iran's apparent regional ambitions.
His father, King Salman, was the first world leader to host Trump -- and he did it in style.
In May, he literally rolled out the red carpet for Trump in Riyadh, put on a traditional sword dance for him and invited dozens of Muslim nation leaders to a grand conference.
The King and his son understand Carnegie's premise: Cooperation comes easier with friends. For them, an American president who shares their antipathy toward Tehran is a valuable ally --, and they are right.
Iran's backing of the Houthi rebels in Yemen has been increasingly exposed. A recent UN report said the theocracy supplied the rebels with the long-range ballistic missiles they have been firing at the Saudi capital.
Riyadh says Iran also has helped the Houthis attack an oil tanker in heavily trafficked Red Sea shipping lanes as well as supplied them with clandestine cash-printing machines upending the Yemeni economy.
These developments further Trump's narrative of Iran as a regional agent of terror. For the Saudis, it makes their concerns about Iranian interference in Yemen better appreciated.
Indeed, it has been in the Middle East where Trump's ability to make friends has had the biggest impact
After Saudi Arabia, the next stop on his maiden overseas venture was Israel. Months later, he declared Jerusalem as Israel's capital, which was warmly received by the majority of Israelis.
The Palestinian response was initially muted, but absent a follow-on strategy, the decision is setting Palestinian leaders against Trump and raising concerns among respected Muslim scholars of an angry backlash of "increasing terrorism" over the longer term.
Just a few weeks after Trump came to office, the European Union's 28 leaders held an emergency meeting in Malta.
It was already clear that their old friend America was changing under Trump.
German Chancellor Angela Merkel and then-French President Fran-ois Hollande announced that the EU needed to be ready to chart its own course.
By the end of Trump's first year, he has embarrassed Merkel and wrangled with President Emmanuel Macron, Hollande's successor.
British Prime Minister Theresa May has seen her relationship with the US President, supposedly special, go from hand holding at the White House to being scolded in a tweet for not minding her own business.
According to a new Gallup Poll, approval of US leadership across 134 countries and areas is at a new low -- 30% -- down from 48% in 2016.
The message for America's friends going forward is hard to miss.
The UK foreign policy think tank Chatham House headlined its new report on US-European relations with the guidance "Think beyond Trump."
Chatham House reinforces Merkel's advice to EU leaders that in the absence of Trump's global leadership, Europe should follow its own principles of decency, democracy and free trade.
The Gallup Poll elevates Merkel to the world's most trusted leader spot -- ahead of the United States, China and Russia.
As Trump and America's standing has receded, Russia has spent the year trying to pick up the slack.
It not clear if President Vladimir Putin cares two hoots for Carnegie's playbook about making friends, but he is ambling along behind Trump, picking up discarded opportunities where he sees them.
Only this week, the Kremlin offered to insert itself into American affairs in Afghanistan, announcing it is ready to help the Taliban and Afghan government negotiate peace between them.
It's hard to imagine that the Soviet bear, which slunk out of Afghanistan with his tail between its legs almost three decades ago, has been reincarnated today and is offering assistance to the men whose fathers and grandfathers likely drove them out.
Yet this is what a year of Trump has helped achieve -- a reset of global order of friendship and the advent of a new era of uncertainty.
In trying to deal with his Afghanistan problem, Trump is presenting Pakistan a tough take-it-or-leave-it choice: Fight terrorism as we say or forgo military aid.
Pakistan has long been a squirrelly partner for US presidents to deal with. National interests have only partial intersection, and compliance with US wishes has only ever been that -- partial.
While other US leaders have stepped more carefully around Pakistan's sensitivities, Trump is trampling right over them. Yet the Pakistanis may stand between the United States and a stable Afghanistan.
Pakistan's leaders have already taken the tone of injured ally, meaning Trump is pushing away an erstwhile friend.
As in Jerusalem, if Trump's sacrifice of friends to shake up stalemated situations is backed by a solid strategic gambit, he may prove Carnegie wrong. His remaining friends may forgive him, he may win others over, and perhaps more importantly for him, he might win back his fabled dealmaker image that he so cherished before becoming President a year ago.