Travel does not always broaden the mind, but it can sharpen perspective. Recent weeks have taken me to Germany, France, the Netherlands and Spain. I learned much about these very different countries, but the most important takeaway was about my own. The largest conclusion I drew from recent conversations on the continent is that Europe is no longer terribly interested in these islands. How much attention are our closest neighbours paying to what is happening to the United Kingdom? Not much, in truth.

The week ahead in Britain will see the energies of its parliament expended on the latest developments in a Brexit plot that is becoming hideously complex even for those of us paid to follow it. Exactly like the week just gone then. No different to many weeks previously. Breathless news bulletins bring the latest about the drama of tight parliamentary votes along with threatened cabinet resignations and actual ones lower down the political food chain. Reporters endeavour to explain to head-scratching viewers why the cabinet is angrily divided over “time-limiting the backstop”. Theresa May thinks it a good night’s work when she survives to prevaricate another day. Jeremy Corbyn achieves the unusual feat of splitting Labour MPs three ways over a key vote on what kind of Brexit we should be having. The Westminster air grows fetid with tales of last-minute bargains and stories of betrayal. The characters alternate between insulting each other in the most vitriolic language and torturing us with rival ways to define “a meaningful vote”.

A 'no deal' outcome would be grisly for many EU countries as well

This is hard enough to make sense of if you are British. Hayley Hughes of Love Island has been much mocked for admitting she is baffled by Brexit. The ridicule was unreasonable. After all, the people who are supposed to be in charge of Brexit, the contestants on the Hate Island that is the Tory party, don’t appear to have a clue either. The negotiations with Brussels are stalled because the cabinet is still not agreed on which form of customs arrangement to propose for rejection by the EU.

Even the natives are struggling to keep a grip on this surreal soap opera. How much less accessible is the grisly show to anyone tuning in from elsewhere? The comic English eccentrics who were introduced to amuse foreign audiences have ceased to raise a laugh. Boris Johnson just isn’t funny any more.

The continental shrug was not always the case. In the immediate aftermath of the referendum – a long and painful two years ago – there was much fascination with what was happening here. From princes to paupers, just about everyone on the continent had an opinion about Britain’s narrow decision to self-amputate itself from the EU. Many were taken aback by a choice that ran counter to the stereotype of a nation of level-headed pragmatists who prized orderly stability above most things. Many were dismayed and puzzled and echoed the hope expressed by Donald Tusk that somehow the decision might be reversed. Some, particularly Germans, were wounded that Britain had chosen divorce. Others, the ardent integrationists in Brussels, were happy to say good riddance to the EU’s most truculent member.

Twenty-four months later, I’d say lack of interest is the primary response to Britain. For Ireland, unwillingly pressed on to the frontline by geography and economics, this is not the case, because a bungled Brexit will have nasty consequences for the republic. Elsewhere in Europe, the initial shock has numbed into indifference.

This is less true as you move up the ladder of financial and political power. Business leaders, people in government and other decision-makers are still giving it some attention. They are conscious of the scale of the stakes. The most horrible consequences of a car-crash Brexit would be felt on these islands, but a “no deal” outcome would be painful for many EU countries as well. It is not just German business that has cause for concern about the negative consequences for trade and investment of an acrimonious British departure. Even so, even among business and political leaders, there is diminishing patience with what is seen as a second-order issue for Europe. Viewed from Berlin, Paris, Rome, the Hague or Madrid, the theatrics at Westminster are of marginal interest compared with the mounting strategic challenges facing the EU.

Italy is too important to the EU to be allowed to fail but too large to be saved

There were always more important things for most Europeans to be anxious about than the islands on the north-western shore of the continent. They are concentrating their minds on those, rather than trying to fathom the unfathomable intents of this country and its flailing government. George Soros goes so far as to say that the challenges facing the EU amount to “an existential crisis”.

Europe is confronted with a growing and increasingly grave crisis over immigration. Authoritarian governments in Hungary and Poland are defying founding principles of the EU. Vladimir Putin, who would achieve a major geopolitical triumph if the EU started to break up, will be on his best behaviour only for the duration of the World Cup. The best-case scenario about the new government in Italy is that it doesn’t last long enough to wreak too much havoc. Italy is too important to the EU to be allowed to fail but too large to be saved. A financial meltdown in Europe’s fourth largest economy would merit the adjective existential. The German chancellor, Angela Merkel, for long the most powerful fixed point in European affairs, is struggling to sustain her domestic coalition. France’s Emmanuel Macron has been better at generating a vision for reviving the EU than at winning support for his ideas among other key leaders.

Then there is Donald Trump. The fear he induces in Europe makes Brexit look trivial and Britain’s decision to quit the EU even more misjudged. The poisoned G7 summit in Quebec has left relations between the US and its historic allies in the democratic world in a darker place than at any time in living memory. Even by his standards, it was a special achievement for the American president to viciously insult Canada en route to lavishing praise on North Korea’s totalitarian-in-chief. There is trepidation in European capitals about what will unfold when the American president is next thrown into proximity with other leaders at the Nato summit in July.

The Trump-triggered escalation towards a global trade war emphasises how marginalised Britain has become

It used to be the conceit of British prime ministers that they could be a transatlantic “bridge” between Europe and the US. This was often delusional, but occasionally bore some relation to the truth. No one in Europe now looks to Theresa May to be a go-between with Donald Trump. Any British prime minister would find it hard to navigate a relationship with a volatile occupant of the White House who is so cavalier about its traditional alliances. It is not Mrs May’s fault that her premiership has coincided with the Trump presidency. It was Britain’s decision to detach itself from its continental neighbours just at the time when America went rogue.

The Trump-triggered escalation towards a global trade war emphasises how marginalised Britain has become and what a perilous place the world can be for a medium-size state without reliable allies. Trade wars are waged by elephants; smaller animals get crushed underfoot. Rounds of destructively macho tit-for-tat tariff retaliation makes the climate even less clement for striking a decent deal with the EU. Trumpian belligerence exposes what a fantasy it was to believe that Britain only had to shake itself free from Europe to conjure up golden trade deals with the rest of the world.

We could conduct a thought experiment and wonder what part Britain might be playing on this turbulent planet had the country made a different choice in the summer of 2016. Britain could be having an influential role in shaping what sort of Europe, what sort of world, emerges next. A British voice might have been a powerful one urging and helping Europe to defend shared values and interests against authoritarianism, nationalism and protectionism. The cost of leaving the EU will be counted not just in pounds and pence but also in influence forgone. The British political class is too consumed by Brexit to think about the world. The world has bigger things on its plate than Brexit.

A fractured planet is in great flux. Many of the things we have taken for granted about the international order over many decades are in play. Where the pieces ultimately land will have profound consequences for these islands. And where is Britain? Britain is busy with a bunfight at the bottom of its own navel.

• Andrew Rawnsley is an Observer columnist