US role as global leader looks over - and we will miss it more than most
Years ago, a mate of mine, the son of a hard-working Jewish butcher from Brooklyn, managed to get into Harvard. This was a huge undertaking for this average family without the financial resources to pay Ivy League fees. But they managed, as families tend to do. They saved, scrimped and borrowed so eventually the son emerged from one of America's finest universities with brilliant results. He hasn't looked back since.
Two decades later in New York, when we were chatting to his dad, discussing the sacrifices parents have to make to send their kids to top US universities, the old man looked at me and chuckled: "If you think Harvard is expensive, try ignorance!"
Ignorance is expensive and Donald Trump is testament to this. By pulling out of the Paris Climate Accord yesterday, he is signalling to the world that the United States - for so long the world's pre-eminent home of scientific enquiry - is rejecting science. For the country that sent the first man to the moon, this is shameful. American universities produce far more Nobel Prize winners for science than the rest of the world combined - what does this say to them?
Having a climate change denier in the White House is frankly embarrassing.
There is also something bigger about the US withdrawing from the world. It is a massive change from everything that has gone before. We will miss America if it goes.
Pax Americana has given the world its geo-political ballast for the past 70 years. Implicit in this is the understanding that the USA - initially the world's major and then the world's only superpower - would defend concepts like free trade, free movement of people, freedom of the press, and multilateral organisations like the UN and the World Bank.
For most of the EU's existence, peace in Europe was preserved by the fact that the Americans deployed its military up against the Iron Curtain. Does anyone really think that Western Europe's military would have given Soviet generals a sleepless night? Of course not! Nato, as much as the European Union, created the conditions for peace in Europe. Nato is an American creation.
Likewise in Asia, the ability and willingness of America and, in particular, the US Navy, to project its power to the farthest corners of the globe preserved peace in Asia.
Obviously, the Americans have made mistakes. Indeed it is deeply fashionable to list our grievances against the Yanks. However, that "what aboutery" approach is to fall into the great critics' trap of failing to distinguish between good and best. Sure, we'd all love to be best, but in many cases, being good as opposed to bad is sufficient. Being best is an aspiration and a rare reality.
The Americans operated a foreign policy for much of their hegemony known in Washington as "adult supervision". This summed up the American approach to allow all the smaller countries, former friends and foes alike, to mess around in the playground until there was an issue. Only then would America step in and do the right thing. This strategy was most evident for Europeans during the genocidal war in Yugoslavia. In Yugoslavia, even as innocents were being slaughtered on our TV screens, the so-called European powers of Germany, Britain, France and Italy sided with their old allies, either Serbia or Croatia, claiming impotence as a drunk and vicious rabble murdered and raped.
Finally, it was Bill Clinton who decided this was enough; and the Americans bombed the Serbs to the negotiating table as the Europeans looked on with fake indignation.
For Irish people, Pax Americana was most evident in the North. It wasn't European politicians who sat down tirelessly with the various sides in Northern Ireland between 1994 and 1999. It was Americans.
The Americans involved themselves, mainly on the nationalist side, giving our government a friend in the negotiations. It was American politicians who helped with the furious scurrying back and forth between Dublin and London, helping clear obstacles. I can't remember a continental European politician becoming seriously involved, can you? Do you remember names like Jacques Chirac, Eduard Balladur or Gerhart Schroeder in the Good Friday Agreement?
As you can see, at crunch times, the American adults came in to supervise the unruly children and sort things out.
Part and parcel of American hegemony has always been trade and capital flows. Over the years this has culminated in Ireland doing $90bn (€80bn) of trade with the US every year. This is a phenomenal figure, particularly when you place it on top of the close to $400bn (€354bn) in US foreign investment here.
Unfortunately, the global understanding whereby the US will always be there as a type of "underwriter of last resort" is disappearing with Mr Trump. As I said, let's not confuse best with good; the US has made plenty of mistakes as the global policeman, but if it leaves the pitch we will miss it.
So how serious is Mr Trump about leaving the pitch? If his Irish-American puppeteer Steve Bannon has anything to do with it, withdrawing from the Paris Accord is only the start.
Mr Bannon is a true radical. He is on record as saying he wants to destroy and disrupt the "status quo" both within America and outside it. He wants to tear up agreements that he believes were hatched over the head of the ordinary American yet signed in the name of the ordinary American. He is the Nativist in the administration who believes that the people have been betrayed by a ruling class which sits above democracy, ultimately looting the country for its own narrow ruling class.
For him, American commitments to agreements such as the climate change accord, the UN, Nafta and Nato are simply various ways of emasculating American sovereignty.
Mr Trump repeated these Bannon mantras time and again in his campaign and it seems that when he is under pressure in Washington and needs a quick headline, he lurches for the Bannon playbook, whether it's a renewed immigrant ban or withdrawing from an international treaty.
This is all very dangerous for us, because Ireland has benefited overwhelmingly from Pax Americana. We are umbilically tied to the US. Furthermore, any withdrawal of America from the world stage would leave the world a much more dangerous place.
Germany, the only other possible Western hegemon, hasn't the permission to lead properly; or at least the Germans have shown no appetite for the constraints and costs of leadership.
Those who are now looking to China to take up the global reins should be equally cautious: China is an autocratic, one-party state on the cusp of a financial meltdown. To paraphrase an elderly man: "If you think America is bad, try China!"