The two “ghost ships” discovered sailing towards the Italian coast last week with hundreds of migrants – but no crew – on board are just the latest symptom of what experts consider to be the world’s largest wave of mass-migration since the end of the second world war.

Wars in Syria, Libya and Iraq, severe repression in Eritrea, and spiralling instability across much of the Arab world have all contributed to the displacement of around 16.7 million refugees worldwide.

A further 33.3 million people are “internally displaced” within their own war-torn countries, forcing many of those originally from the Middle East to cross the lesser evil of the Mediterranean in increasingly dangerous ways, all in the distant hope of a better life in Europe.

“These numbers are unprecedented,” said Leonard Doyle, spokesman for the International Organisation for Migration. “In terms of refugees and migrants, nothing has been seen like this since world war two, and even then [the flow of migration] was in the opposite direction.”

European politicians believe they can discourage migrants from crossing the Mediterranean simply by reducing rescue operations. But refugees say that the scale of unrest in the Middle East, including in the countries in which they initially sought sanctuary, leaves them with no option but to take their chances at sea.

More than 45,000 migrants risked their lives crossing the Mediterranean to reach Italy and Malta in 2013, and 700 died doing so. The number of dead rose more than four times in 2014 to 3,224.

“We know people who died – they used to live with us,” said Qassim, a Syrian refugee in Egypt who now wants to reach Europe. “But we will try again to cross the sea because there’s no life for us Syrians here.”

In Egypt, up to 300,000 refugees from the Syrian war were initially welcomed with open arms. But after Cairo’s sudden regime change in summer 2013, the atmosphere turned drastically, leading to rampant xenophobia against Syrians and increased arrests and detentions of those who, for understandable reasons, did not carry the correct residency paperwork.

The situation is even worse in Jordan and in Lebanon, which now houses more than 1 million Syrian refugees – more than a fifth of the country’s total population.

Their presence has created an unprecedented strain on national resources, leading to the Lebanese government tightening restrictions last week on Syrians entering the country. And while Turkey has simultaneously moved to strengthen refugees’ rights, Turkish shores are likely to remain a popular launch pad for migrants looking to reach Europe because of both the comparatively high cost of living, as well as rising xenophobia, particularly in the country’s south.

Libya, another major point on the migration route from the Middle East and north Africa, is also no longer a safe haven after a civil war erupted there last year. The plight of refugees there, as well as across the region, makes a mockery of those who suggest the wave of migration is caused simply by economic migrants.

“If they’re economic migrants,” asked Doyle, “then how do we explain that after every outbreak of violence and repression we get a new wave of people from the area that’s just had that outbreak? Why was it that, in the huge September disaster in the Mediterranean, the people who drowned were Palestinians, just a couple of weeks after the war between Gaza and Israel? And why is it that since last year there has been a steady flow of people from Eritrea, when we know there are serious problems in that country?”

But such arguments have yet to convince the British government, which refused last October to help Mediterranean rescue operations, and which by last June had admitted fewer than 150 Syrian refugees.