Image copyright AFP/Getty Images

As Donald Trump becomes US president on Friday many will reach for a drink. Washington DC will be whirl of parties, galas and balls.

The celebrities may be skipping it this year but the US capital will still swing to the sound of clinking glasses and popping corks. Across the country, celebrating Trump supporters will toast his swearing-in with a drink while others will numb their nerves with booze.

Around the world, alcohol will help with this historic transition. In north London, for instance, the Old Queens Head pub is throwing an Armageddon-themed party to mark the start of Donald Trump's presidency.

But the man himself will not be boozing through his first hours as the most powerful politician in the world. In fact, he won't touch a drop of alcohol on Friday night or on any day of his presidency.

"I've never had a drink," Donald Trump told Fox News after his election last November. Unlike George W Bush, who was teetotal in office after giving up booze on his 40th birthday, Mr Trump has eschewed alcohol his whole life, making him a first among modern US presidents.

Image copyright Joe Raedle/Getty Images Image caption Donald Trump's teetotalism stems from the early death of his older brother Freddie

The reason for Mr Trump's sobriety is because his adored older brother Freddie died of illness stemming from alcoholism at the age of 42. "It was a very tough period of time," he said, that convinced him never to drink.

"If you don't start you're never going have a problem. If you do start you might have a problem. And it's a tough problem to stop," Mr Trump told Fox.

What is fascinating is his view that one drink could spiral into addiction. He discussed his fear that he might have a gene that would make moderate drinking impossible.

His approach to alcohol is also a window into a personality that appears to crave control over others. Mr Trump ordered his children to follow his example. Every day he would drum the message into them: No drugs, no alcohol, no cigarettes. "I've been very tough on my children with respect to drink," he said.

So how do the teetotal presidents compare with those who enjoyed the pleasures of a drink? George W Bush went dry after years of heavy boozing and swapped a compulsion for drink for an obsession with fitness.

Remembered largely for the invasion of Iraq, George W's foreign policy record might not be seen as the best advertisement for a teetotal presidency.

Image copyright Fox Photos/Getty Images) Image caption Franklin Roosevelt (right) had a particular reverence for "cocktail hour"

Nor might the idealistic but muddled foreign policy of Jimmy Carter, another teetotal president. Life in the Carter White House was drearily dry and a chore for its more sociable visitors.

Senator Ted Kennedy remembered arid evenings of earnest discussion. "You'd arrive about 6.00 or 6.30pm, and the first thing you would be reminded of, in case you needed reminding, was that he and Rosalynn had removed all the liquor in the White House. No liquor was ever served during Jimmy Carter's term. He wanted no luxuries nor any sign of worldly living," Kennedy wrote.

The moderate drinkers fare better. Franklin D Roosevelt frequently tops the list of America's greatest presidents, the commander-in-chief who defeated the Great Depression and led the US through World War Two.

Throughout these turbulent years, FDR kept a martini close at hand and prized the rituals of cocktail hour, when he mixed stiff drinks for friends on his White House study desk. The conviviality of cocktail hour undoubtedly helped FDR unwind and briefly relieved the immense pressure he was under.

John F Kennedy would occasionally sip a daiquiri but preferred women to wine and kept a clear head through the brinkmanship of the Cuban Missile Crisis. But other presidents were more reckless with their drinking.

Image copyright National Archive/Getty Images Image caption Both Johnson and Kennedy enjoyed a drink

Lyndon Johnson was well known in Washington for his capacity to guzzle Cutty Sark whisky and soda when he was Democratic majority leader in the Senate, a habit he took to the White House. Johnson, who told his doctor after a heart attack that the only things he enjoyed in life were "whisky, sunshine and sex", enjoyed entertaining at his Texas ranch where the booze flowed.

LBJ's special assistant for domestic affairs, Joseph A Califano, remembered a ride around the ranch with the president: "As we drove around we were followed by a car and a station wagon with Secret Service agents. The president drank Cutty Sark scotch and soda out of a large, white, plastic foam cup.

"Periodically, Johnson would slow down and hold his left arm outside the car, shaking the cup and ice. A Secret Service agent would run up to the car, take the cup and go back to the station wagon. There another agent would refill it with ice, scotch and soda as the first agent trotted behind the wagon."

But the most disturbing picture of presidential drinking is provided by Richard Nixon, a man prone to morose self-pity who medicated his moods with booze.

According to his Secretary of State, Henry Kissinger, Nixon's trouble was that a small amount of drink would set him off and late-night threats of military action were made when the president was the worse for wear.

When North Korea shot down a US spy plane in April 1969, an enraged Nixon allegedly ordered a tactical nuclear strike and told the joint chiefs to recommend targets. According to the historian Anthony Summers, citing the CIA's top Vietnam specialist at the time, George Carver, Henry Kissinger spoke to military commanders on the phone and agreed not to do anything until Nixon sobered up in the morning.

Image copyright AFP/Getty Images Image caption Henry Kissinger allegedly witnessed the effects of Richard Nixon's drinking

By the early 1970s, Watergate was beginning to choke Nixon's presidency and the president was relying more on drink and sleeping pills to cope with the pressure. On the evening of 11 October 1973, he was incapable of speaking to the British Prime Minister Edward Heath on the phone.

Heath was keen to discuss the latest developments of the Arab-Israeli War but a transcript of the conversation between Henry Kissinger and his assistant Brent Scowcroft revealed the president was too drunk to talk to the prime minister.

Richard Nixon was a warning to future presidents on the danger of mixing hubris with drink. He is a reminder too of the awesome executive power a US president has when it comes to conducting foreign affairs.

With no previous political or military experience, Donald Trump is unlike any incoming president. His hubris is clear to all and his (sober) stream of excitable tweets prove an impetuous temperament.

Nixon's example might make us grateful booze is not in the mix too. But some of the most successful presidents found valuable perspective and balance at the bottom of a glass.