When it comes to dealing with Donald Trump, European leaders should turn to parents of toddlers for advice.

As any three-year-old can attest, there are times when throwing your toys out of the pram is an excellent negotiating strategy. In other situations, it simply limits your supply of fruit gums.

The challenge for parents is to reduce the opportunities for unavoidable concessions. These include busy supermarket lines and long-haul flights. In all other circumstances, presenting a united front does the trick.

The European family is of course going through a period of extreme dysfunction. A messy divorce has triggered a heated debate about its future. The question of what to do with the hundreds of thousands of people who have sought refuge or a better life in its midst has polarised opinion and sparked questions about whether Europe can even be considered a family at all anymore.

At a time of low morale, a good rallying cry can work wonders. No one knows this more than Donald Trump. His promise to ‘Make America Great Again’ managed to combine hope for a better future with indignation for his country’s faded glory.

Hope and indignation are powerful political forces, which Europe has so far failed to package into a digestible message of 140 characters.

This is a pity because as any social media professional will tell you, messages of hope and indignation have a tendency to spread.

In November of last year, Irish Labour politician Aodhán Ó Riordáin shot to Internet fame after he posted a video of himself lambasting Donald Trump. “America has just elected a Fascist,” he told the handful of senators gathered in the Dublin chamber. “And the best thing the good people of Ireland can do is ring him up and ask him if it’s still okay to bring the shamrock on St Patrick’s Day.”

Fast forward a few months and the taoiseach (prime minister) Enda Kenny found himself in a bit of a pickle on St Patrick’s Day. Ingratiate himself with Donald Trump for the sake of the economy like his British counterpart Theresa May, or stand up to him and earn brownie points at home? He opted for the latter and extolled the virtues of St Patrick, the immigrant.

His speech too went viral.

These examples demonstrate the extent of an appetite in Europe – and beyond – for an unequivocal response to Donald Trump.

A day after Enda Kenny’s visit to the White House, it was German chancellor Angela Merkel’s turn. When Trump ignored her request to shake hands for the cameras, she responded with the kind of bemused expression one might direct at a sulky child who has rebuffed their caregiver’s command to “say hello to Auntie Angie.” Once again, the Internet exploded in delight.

The positive attention such encounters have attracted prompts a provocative question: could Donald Trump Make Europe Great Again? (#MEGA)

The answer is that he could, if European leaders keep three important things in mind.

First, they must show that despite Brexit, the continent remains bound by common values.

While many Europeans found British Prime Minister Theresa May’s charm offensive in Washington cringe-inducing, there was widespread respect for the decision by John Bercow, the Speaker of the House of Commons, not to welcome Donald Trump to address parliament during his return visit. For pro-Europeans, this was a welcome reminder that the UK’s divorce from the EU has not made it an unquestioning bedfellow of the United States.

The next thing leaders must do is take serious action to stem the rise of the Trump-loving far right at home.

On this front, there are reasons for cautious optimism.

The defeat of the far-right populist Geert Wilders in the Dutch elections in March was a promising start. Then in France’s presidential elections in May, Emmanuel Macron, an unapologetic fan of the EU, scored a decisive victory over Marine Le Pen, who had threatened to leave the bloc.

The selection of former European parliament president and crowd pleaser Martin Schulz to challenge Angela Merkel in Germany’s upcoming elections makes it a near certainty that the continent’s most powerful economy will continue to be led by a Europhile.

The third and most important thing Europe must do is launch a major PR campaign.

Ignorance of what the EU does and what it stands for remains embarrassingly widespread.

Here it can learn a thing or two from Donald Trump, who leaves little need to speculate about what it is he believes.

With European identity abstract by definition, social media provides an ideal opportunity to present the spirit, if not the nuts and bolts, of European identity.

If there was any doubt before, Britain’s decision to leave the EU confirmed that Europe is in disarray. But hitting rock bottom is often what it takes for a family to pull together. After all, the only way to withstand the outrageous demands of a screaming toddler is with a united front.