For many in the aviation industry and in Europe, the Taoiseach's comment that UK planes "would not fly" in the event of a no-deal Brexit was nothing more than a statement of fact.
"The situation at the moment is that the United Kingdom is part of the single European sky, and if they leave the EU they are not, and that does mean that if there was a no-deal, hard Brexit next March, the planes would not fly and Britain would be an island in many ways and that is something that they need to think about," Leo Varadkar said in Kerry three days ago.
“You cannot have your cake and eat it. You can’t take back your waters and then expect to use other people’s sky.”
On the pro-Brexit side his comments were interpreted as an attempt at blackmail; a threat that if British prime minister Theresa May insists on taking back exclusive fishing rights for British waters, our revenge will be to unilaterally close the skies.
Conservative MEP David Bannerman called Varadkar's comments "shameful blackmail" while DUP MLA Christopher Stalford tweeted: "Hilarious! Does he actually think anyone with half an ounce of sense or self-respect would be bullied by the likes of this?"
The harshest response came from the Sun newspaper which on Friday branded the Taoiseach "an airhead" (quoting Brexiteer MP Jacob Rees-Mogg) and "a fool".
The paper's editorial read: "Varadkar must believe that these grenades he brainlessly lobs into the Brexit negotiations help Brussels. He is not bright enough to realise how absurd and unstatesmanlike he looks."
It is not the first time the UK tabloid has had a go at Varadkar over his perceived intransigence on Brexit; a previous editorial called him “gobby” and advised him to “grow up”.
What most of this commentary appears to ignore is that if there is a no-deal Brexit, and that is a growing possibility, Britain will leave the European Union and all its accompanying regulations and treaties, with no arrangements to take their place, including in the area of air travel.
This is not a threat from the Taoiseach, it is an obvious fact. No deal means UK airlines will be effectively barred from the airspace of every remaining country in the union.
Varadkar is repeating what has been said by many others including the head of Ryanair, Michael O'Leary, himself no great fan of the EU. O'Leary warned earlier this year that planes might not fly between the European Union and the UK after the March 2019 deadline for Brexit.
More importantly, the European Commission and the Irish Aviation Authority (IAA) have said UK flights will be unable to land in any EU country in the absence of a new deal.
"If a hard Brexit occurs, there would need to be a new agreement in place to maintain the existing level of connectivity between Europe and the UK," an IAA spokesman told The Irish Times.
Looking to the World Trade Organisation would be pointless, he said. Its treaties do not cover the aviation industry.
Downing Street points to the Chicago Convention to which both Ireland and the UK have signed up. However, that guarantees only the rights of airlines to fly over countries, not to land or take off from them.
Negotiations and treaties
The current EU aviation system, with its low fares and wide variety of choice, is probably taken for granted today. It is forgotten that we got to this point by way of decades of complex negotiations and treaties which make it possible to travel to Barcelona for less than the price of the train to Cork.
The 1992 package of reforms, which came about largely because of the work of the UK, was probably the most important step in that process. It severely limited State aid to flag carrier airlines and opened the way for the Ryanairs and Easyjets of Europe to revolutionise the industry.
The next big leap forward was the 2007 EU-US Open Skies Agreement which greatly increased the number of flights to and from America which led to significantly lower fares.
The EU also has Open Sky-style agreements with 16 other non-EU countries including Canada, Norway and Israel.
That means if there is a no-deal Brexit, the UK will also have to renegotiate arrangements with every one of these countries individually. Negotiations with the US have already started with early reports suggesting the UK will get a worse deal than it currently enjoys as part of the EU.
Most observers believe some sort of air-traffic arrangement will be agreed between the EU and the UK, even in the event of an otherwise “no-deal” Brexit simply because the alternative is so unthinkable.
But if we have learned anything since June 2016, when the British people voted to leave the EU, it is to prepare for the unthinkable.