What would you do if Isis was approaching, and safety was only 70 miles across the sea?

Britain likes to pose as a force for decency in the world, but it's permitting hundreds of desperate people to needlessly die

Migrants are rescued off the coast of Sicily by Italian Coast Guards on Wednesday; 5,302 migrants have arrived from Libya since January (Getty Images)

The statistics and stories are so extreme they barely register any more. In just five days, 4,200 migrants were plucked from rickety boats packed nightmarishly full as they made the perilous trip across the Mediterranean - the equivalent of one person every two minutes.

Many had spent dangerous months crossing deserts, dodging lethal militias and then trusting lives to rapacious traffickers. But as they slept outside in soggy clothes on a mid-winter night having made the promised lands of Europe, they were the lucky ones.

For whatever their futures, at least they were alive. Dozens more drowned in those rough, icy waters, lonely deaths on the world’s most lethal route for migrants. Their bodies lined an Italian harbour as hearses queued to take them to an old airport converted into a temporary morgue.

Another 29 people lost their lives after they had been rescued, dying of hypothermia on the decks of small coastguard vessels fighting valiantly to save them in extreme weather conditions.

But they are only Arabs and Africans, so their lives seem not to count for much in Europe. For that is the only conclusion that can be drawn from the cloud of silence over these ceaseless deaths as human beings risk everything in their search for the sort of stable lives taken for granted by people in Manchester, Milan or Munich. Yet many of these unfortunates might still be alive today were it not for crass political expediency in a climate of fear over immigration.

Four months ago Foreign Office minister Baroness Anelay announced Britain would not support search and rescue missions to stop migrants drowning in the Mediterranean.

The justification was simple: such services only encourage desperate people to make the treacherous trip. "We believe that they create an unintended pull factor, encouraging more migrants to attempt the dangerous sea crossing and thereby leading to more tragic and unnecessary deaths," she told the House of Lords.

This sounded a spurious argument to cover a callous decision of astonishing inhumanity, rightly condemned by Labour leader Ed Miliband. And now we can see the stark evidence that proves this policy of supposed deterrence has failed since the end of Mare Nostrum, the Italian rescue operation that helped save an estimated 150,000 lives. It was replaced by Operation Triton, far more limited in scope with fewer and smaller boats patrolling only close to the shore, funded by just one-third of the budget.

Just look at the disturbing data issued by the United Nations. In the first six weeks of this year the number of people known to have attempted the crossing more than doubled on the previous year from 3,338 to more than 7,000.

This is bad enough. But far worse is the number of confirmed deaths, which soared from 12 over this same period last year to 373 this year - a rise of more than thirtyfold.

Among them were those 29 people who froze to their deaths as waves washed over them during an 18-hour rescue mission.

‘If Mare Nostrum were still going, the migrants would have been given shelter inside a large ship within an hour,” said Giusi Nicolini, mayor of Lampedusa, the Italian island on the frontline of this crisis. But still the boats keep coming: from crammed plastic craft that should never attempt such a crossing to ghastly ‘ghost ships’, those ancient rustbuckets abandoned by crews to leave their huddled human cargo helplessly drifting.

One UN source told me it was "nuts" to suggest there was a "pull factor", which is underlined by these depressing figures. We are, after all, living amid the greatest refugee crisis since the Second World War, with some 50m people forced from their homes and worsening violence and repression sweeping across the Middle East and Sahel.

It stretches credibility to suggest that despairing people fleeing savage groups such as Isis and Boko Haram are pondering the standard of rescue services before paying small fortunes to smugglers to save their families and salvage wrecked lives.

Ask yourself what you might do, trapped in one of these horror stories, seeing security and prosperity just 70 miles away over the sea. And as turmoil spreads in Libya, with the longest coastline of any southern Mediterranean country, this is a crisis that can only worsen.

Britain likes to pose as a force for decency in the world. But permitting hundreds of people to die is simply immoral, especially when driven by domestic politics and from a country that sent its forces into battle in two of the nations worst afflicted by bloodstained chaos.

Yes, the Government has given aid. But for all the fine talk, fewer than 100 of those fleeing the carnage have been permitted to come here under a scheme to protect Syrians most at risk. Germany, by contrast, agreed to take 30,000 - while some countries neighbouring Syria have seen populations swollen by almost a quarter.

The European Commission last week agreed extra funds to ensure Operation Triton keeps going until the end of the year. Sadly, it is still far too little and comes too late. These are, of course, immense challenges with no simple solutions. But this mammoth tide of human misery and desperation is not going to stop in the near future. So how will history judge this doomed attempt to pull up the drawbridge on Fortress Europe, regardless of all those corpses left floating in the sea like sordid human flotsam?