The leaders of the free world were on holiday this week. David Cameron enjoyed a relaxing break in Portugal, while Francois Hollande disappeared to Provence with his family.

Meanwhile, Barack Obama left Washington for two weeks on the golf course. He was looking forward, he told reporters, to not wearing a suit for a while.

But while the leaders of the West were sipping cocktails and basking in the sunshine, the world burned.

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As Iraq continued to slide into blood-drenched anarchy, thousands of people remained trapped in the mountains by the advance of Islamic State militants

The picture allegedly shows militants of the Islamic State of Iraq and the Levant (ISIL) murdering dozens of captured Iraqi security forces members

Twelve days ago, we remembered the outbreak of the First World War, the conflict that was supposed to end all wars.

Yet despite the pious hopes of the centenary services, this has been a summer of mayhem, slaughter and terrifying instability.

As Iraq continued to slide into blood-drenched anarchy, thousands of people remained trapped in the mountains by the advance of Islamic State militants.

In North Africa, Libya’s parliament begged on Wednesday for foreign intervention to protect civilians from rival warlords, whose feuding has already killed well over 1,000 people.

In Ukraine, as Russian convoys of aid and armoured cars rolled over the border, government forces pounded the rebel-held cities of Donetsk and Luhansk, where water, food and electricity have long since run out.

Masked armed men wearing uniforms with the emblem of the Berkut, Ukraine's bisbanded elite riot police force, block the road near the police station in the centre of Donetsk

And in Syria the bloody civil war, which has already claimed a quarter of a million lives, reached a horrifying new low when an Islamic State fighter posted a picture online of his six-year-old boy holding a severed head.

With every day bringing new atrocities, you might have thought that the leaders of the West would be locked in talks, discussing how to resolve the conflicts that have brought such horrors to the shores of the Mediterranean and the edge of Europe.

Yet not until Thursday did Mr Cameron break off his holiday to return to London. Despite plans to send RAF helicopters to help refugees in Iraq, Parliament has not been recalled.

And, across the Atlantic, Mr Obama evidently believes that practising his putting is far more important than the chaos in the Middle East.

For my part, I am staggered that our leaders have reacted to these months of crisis with such blithe insouciance.

For when future historians look back, they may well see the summer of 2014 as a watershed marking the end of the post-Cold War order, and the birth of a new and far more dangerous era of religious extremism and regional instability.

In the long term, the roots of the current crisis on Europe’s borders, from the cities of eastern Ukraine to the deserts of the Middle East, lie in the hubris and folly that followed the fall of the Berlin Wall, a quarter of a century ago.

When the Wall came down in the autumn of 1989, it marked the end of a long, dangerous but relatively stable stalemate between the democratic West and the communist East.

When the Wall (Checkpoint Charlie in the Wall) came down in the autumn of 1989, it marked the end of a long, dangerous but relatively stable stalemate between the democratic West and the communist East

To the politicians of the day, capitalism had been vindicated, while Marxism had spectacularly failed.

Yet what is now clear is that in the following 25 years, the nations of the West, giddy with naive triumphalism, palpably failed to lay lasting foundations for the future.

To take an obvious example, instead of working to establish a stable democracy in post-communist Russia, the US and Britain allowed Russia to slide into anarchy under Boris Yeltsin and then towards autocratic tyranny under Vladimir Putin.

Instead of working to establish a democracy in post-communist Russia, the US and Britain allowed Russia to slide into anarchy under Boris Yeltsin and then towards autocratic tyranny under Vladimir Putin (above)

And in the Middle East — by far the most fractured, dangerous and strategically important region on the planet — Western policy during the 1990s and 2000s now looks like a disaster.

Instead of coaxing stable but authoritarian regimes such as Egypt and Syria towards democracy, the West preferred to prop up elderly tyrants like Hosni Mubarak and Hafez al-Assad, the father of the current Syrian president. That was folly enough. Even worse, however, was the catastrophically reckless decision by George W. Bush and Tony Blair to topple the Iraqi dictator Saddam Hussein without carefully laying the foundations for a post-Saddam regime.

Deposing Saddam Hussein was a catastrophically reckless decision by George W. Bush and Tony Blair

Alas, we all know the result: an unending saga of car-bombings, sectarian uprisings and bloody massacres.

And now that Islamic State militants have carved out their own territory in western Iraq, the very survival of the country seems highly unlikely.

Mr Blair may deny any responsibility for the carnage in Iraq, but he is in a minority of one.

As his former protégé David Miliband admitted last week, it is ‘clearly the case’ that the bungled occupation of Iraq undermined the foundations of the state, shattered any legitimate authority, and played a key role in creating the carnage we are seeing today.

It is little wonder, then, that so many people in the West have turned inwards, preferring the comforts of isolationism to the hard choices that come when you engage with the world.

And perhaps it is not surprising that Barack Obama and David Cameron, reacting to the shameful hubris of the Blair-Bush years, would rather order a new round of drinks than order their troops into battle.

But, as history shows, you simply cannot wish the problems of the world away.

The last great age of isolationism, after all, was the 1930s, when Hitler, Mussolini and Stalin were in their bloody pomp. We all know how that turned out. Indeed, while Mr Obama’s mantra — ‘Don’t do stupid stuff’ — may sound like an understandable reaction to his predecessor’s oafish blundering, it is no substitute for a foreign policy.

The last great age of isolationism, after all, was the 1930s, when (left to right) Hitler, Mussolini and Stalin were in their bloody pomp

As his former Secretary of State, Hillary Clinton, recently put it: ‘Great nations need organising principles, and “Don’t do stupid stuff” is not an organising principle.’

If you are wondering, by the way, what Britain’s organising principle is, then I am afraid I don’t have an answer.

Ever since David Cameron came to office in May 2010, he has swung from one extreme to another.

At first, he seemed an avowed anti-interventionist, insisting that democracy could not be ‘dropped from the air by an unmanned drone’.

Yet when revolution broke out in Libya in 2011, the Prime Minister promptly sent in the RAF to bolster the rebels, claiming that the alternative would be to ‘pull up the drawbridge’. Similarly, Mr Cameron was a passionate advocate of intervening in the Syrian civil war, despite the glaring absence of either credible allies or a plausible exit strategy.

As his former Secretary of State, Hillary Clinton, recently put it: ‘Great nations need organising principles, and “Don’t do stupid stuff” is not an organising principle’

Indeed, when Parliament blocked his bid to intervene, he sounded uncannily like Tony Blair, snapping that his opponents would ‘have to live with the way that they voted’.

The odd thing, though, is that for all Mr Cameron’s rhetoric, his Government has spent the past four years cutting our Armed Forces.

Despite the growing crises to Europe’s south and east, the Government remains intent on trimming Britain’s regular Army from 102,000 soldiers to just 80,000.

Only a few months ago, the former head of the Army, General Lord Dannatt, warned that ‘with a resurgent Russia, this is a poor moment for the U.S.-led West to be weak in resolve and muscle’.

Alas, I fear that ‘resolve and muscle’ are the last things that Vladimir Putin sees when he contemplates Britain today.

What makes all this even more worrying is that I believe the world is a more dangerous place today than at any time since the early 1980s, when West confronted East across the stark frontiers of the Cold War.

In Russia, for example, I believe there are disturbing parallels with the events that followed the end of World War I in Germany. Of course Vladimir Putin is not Hitler and Russian nationalists are not the Nazis.

But like Germany in the 1930s, Russia seethes with resentment at its perceived humiliation at the end of the Cold War.

And just as many Germans found reassurance in Hitler’s promises of renewed greatness, so many ordinary Russians, their minds warped by the Kremlin’s propaganda, are itching for revenge against their supposed enemies in the West.

So many ordinary Russians, their minds warped by the Kremlin’s (above and St Basil's Cathedral) propaganda, are itching for revenge against their supposed enemies in the West

Given Russia’s vast gas reserves, enormous army and fearsome nuclear arsenal, all that makes for a genuinely terrifying combination.

And if the parallel with the 1930s holds, then I can barely bring myself to contemplate what might happen next.

The terrible events in Syria, Libya and Iraq are part of a pattern, too.

The story beneath the recent revolutions in the Middle East is a toxic combination of a surging population, a stagnant economy, an authoritarian political culture, deep sectarian tensions and a festering sense of anti-Western resentment.

Our politicians had no excuse for not knowing this was coming. Indeed, as long ago as 1994, I remember reading a controversial article in the U.S. magazine The Atlantic Monthly, by foreign policy thinker Robert D. Kaplan, entitled The Coming Anarchy.

Mr Kaplan argued that far from ushering in a liberal utopia, the end of the Cold War would be seen as the beginning of something much more dangerous.

In the long run, he argued, ‘scarcity, crime, overpopulation, tribalism, and disease’ would make the world a far deadlier place.

Given that he specifically mentioned Syria, Egypt and Iraq as future trouble-spots, Mr Kaplan deserves a pat on the back for his prescience.

By and large, I am not a great fan of military interventions abroad. Our recent history, after all, is littered with disasters, from Suez (above, Port Said during the crisis) in 1956 to Iraq in 2003

The tragedy, though, is that the leaders of the West were not paying attention.

I do not believe they are really paying attention now, either. If they were, they would have acted much more decisively when President Putin snatched Crimea and incited his thugs into rebellion in eastern Ukraine, and they would certainly have acted more quickly in Iraq.

By and large, I am not a great fan of military interventions abroad. Our recent history, after all, is littered with disasters, from Suez in 1956 to Iraq in 2003.

It is sheer hubris to believe that we are policemen to the world, and sheer naivety to believe that every story can have a happy ending.

But when they have clear objectives and a universally agreed exit strategy, interventions can work.

We were right to protect the Kurds from Saddam Hussein in 1991 and right to stop Slobodan Milosevic’s massacres in Kosovo in 1999, just as we were terribly, shamefully wrong to have sat on our hands in Bosnia.

The truth is that Western foreign policy has not had a clear direction or decisive leadership since the end of the Cold War.

President George W Bush and Prime Minister Tony Blair were reckless to topple Saddam Hussein without having any apparent idea what to do with a post-Saddam Iraq

Putting aside Tony Blair’s messianic waffle about reordering the world in our own image, we have no idea what our governments stand for, what their priorities are, and where and when they think it necessary to intervene.

In the past, leaders such as Ronald Reagan and Margaret Thatcher — or, indeed, Winston Churchill and Franklin Roosevelt — spelled out their priorities with absolute moral clarity.

True, you may well argue that things were easier for them because the issues were clear-cut: a straight choice between good and evil.

But history suggests that true statesmanship lies precisely in setting out that choice: in taking a moral stand and lifting the fog of ambiguity.

That was what Churchill did when he warned of the horrors of Nazism, and what Reagan did when he called the Soviet Union an evil empire.

What we need now are leaders of the same stamp — men and women with a clear sense of moral conviction, but also a keen awareness of the balance between caution and inaction, idealism and realism, decisiveness and recklessness.

Unfortunately, we have somehow landed ourselves with a generation of political leaders who are more interested in enjoying their holidays than in securing the future of the West.