There are plenty of conservatives right now who offer a wry smile when the subject of Donald Trump comes up. He is President for four or eight years, it is pointed out. Those who cannot accommodate themselves to his strange existence must grow up, runs the argument from those who understandably find the weeping and wailing of the anti-Trump demonstrators wearing. Chill.

Having been through this more than fifteen years ago with George W. Bush, a fully developed adult who unlike the current occupant of the White House had held office before winning, please permit me to say: hold on a minute. I’d rather not “chill.”

Bush was no Trump. He came to office as a compassionate conservative with an appealing credo. Many conservatives in and outside America liked this and the fact that he was not Al Gore. If Dubya sometimes slipped up in speeches it masked a keen political intelligence married with a gift for connecting with voters that made him a much more formidable operator than his critics liked to suggest. Just watch, Dubya fans said, he’ll be better than you think.

And then came 9/11, the immediate aftermath of which he handled well. There was no instant unleashing of hell in the weeks after that tragedy. Instead Bush stayed calm and ordered a clinical operation in Afghanistan that was initially a success. All looked well, for a while. It was shortly afterwards – when Afghanistan was hardly done – that Iraq was mooted. And we all know what happened next.

I mention all this because the Bush experience – and the confident promises made about Iraq – makes me wary of bold and over confident or sophisticated claims made on behalf of disruptive presidents and their potential to be better than it initially seems they will be.

Of course it is not pre-ordained that Trump will be a disaster. In his cabinet are formidable persons such as General Mattis at Defense. But we already know enough, in Trump’s ludicrous tweets aimed at the judiciary, and in his man-child gibbering, to be worried about what his approach to governing will mean for the rest of us outside America.

What can be done about any of this? Outside the US, not much directly. Demonstrations are probably a waste of time in America, although they may fire up the worried and there is evidence it is creating a new movement that could be tapped at future elections. In Europe demonstrations are worse than a waste of time. They are self-indulgent posturing that takes up time better spent working out how Europe might deal intelligently with the new Age of Populism. Europe is spending far too much time virtue-signalling in the direction of Trump rather than cleaning its own house.

Europe, not for the first time, needs to get serious about its defence and security. It has been said so often that Europe spends too little on defence that now it has almost no effect. It’s a standard rhetorical twist, a meaty section in a weighty speech to a foreign policy think tank, that gets everyone nodding before they head off for a glass of warm white wine. And then too little happens.

Last year European defence spending did record its first small rise, but the numbers are still embarrassing Between the mid-1980s and 1989, European Nato countries spent an average of 3.1 per cent of GDP on defence. It fell from there to below 2%. Only five NATO countries – that is the US, Greece, the UK, Estonia, and Poland – hit the 2 percent target set by Nato. Germany is at 1.2 percent but planning more. It should spend a lot more.

What’s the threat? It is two-fold. First, there is Russia to deal with. The great bear that is impossible to invade successfully (too large, full of Russians) has to be dealt with on proper terms. Let’s be realistic. There is no victory, only containment. The best we can ever hope for is that the Russians think we take them seriously and are properly armed and make their policy with that in mind. That means much more European defence spending, now.

Then there is the threat from Islamic State, externally and internally in the form of radicalised maniacs who want to let off bombs in the London tube network and in shopping centres across Europe. This threat crosses borders and is on Europe’s southern border. We are in conflict with an ideology whose adherents want to kill as many of us as possible.

The European Union has had a strange impact on European thinking. It has done the opposite of what was intended by its architects. Rather than making Europe more self-confident and expansive it has infantilised the continent, bogging its leaders down in endless attempts to manage the ill-designed single currency, created by Germany under pressure from France after German reunification, and in efforts to harmonise regulation as it relates to washing machines and much else besides.

The result is a generation of European leaders who seem so overloaded with drivel that they are incapable of thinking clearly. Even the looming departure of the second largest contributor – the UK – seems to inspire only the recitation of rehashed versions of old mantras about the EU’s values.

It has been obvious for a while that there is much more to the future of Europe than Brexit. Europe is not the EU. The EU is not Europe. Russia is on the prowl and American support for Nato is the subject of fierce dispute inside the new administration. A commitment had to be levered out of Trump by Theresa May, the UK Prime Minister, on her recent visit to the White House.

That is an indictment, a warning signal. It is troubling that even securing pathetically half-hearted backing for America’s own Nato project should have been seen as some great win for May and Europe. Even if the next President is not a Trumpian populist, this President has set a course – removing the automatic commitment to alliances – that Europe cannot be sure will be reversed any time soon.

One can talk here about the need for extra European spending in these areas. Of course that must happen, but there is more to it than that. It goes well beyond a monetary calculation. It is an existential question. What is required is a coming together – not under the auspices of the EU, which is of almost no use whatsoever on this stuff – for a practical discussion about how to defend democracy and borders. Such gatherings used to be called great power conferences, although Britain is embarrassingly depleted in defence terms, Germany has a fear of rearmament, and France is fixated on weakening Nato.

Put all that to one side. Once the French, Dutch and German elections are done Theresa May and Angela Merkel, or her challenger Martin Schulz, should convene a great European power conference with whoever ends up winning the French presidential election

It’ll take leadership and bold thinking to reimagine Nato or an alternative. Perhaps it would work out fine ignoring the implications of the Trump presidency and the fraying of American commitment, which began under Barack “leading from behind” Obama, but why take the risk? Europe needs better defence soon. Europe needs to stop mocking an unreliable US. Europe needs to grow up.