By Dominic Waghorn, Sky News Correspondent

Europe has been in the grips of the worst refugee crisis since the Second World War, but it could be about to get a lot worse. That is the perspective from Lebanon, which has taken the brunt of Syria's exodus and is now at breaking point. Coming to the small Mediterranean nation also helps explain why the crisis has suddenly erupted now.

Lebanon is a truly remarkable country. For the last four years, it has absorbed at least a quarter of its population in refugees. While Europeans agonise over a refugee crisis, but a real one has been under way here. Imagine the UK being invaded by the population of London twice over. Refugees are everywhere, camped in fields, lay-bys, beaches and building sites.

Then imagine that in a Britain that hasn't had a functional government for months, where garbage collects in festering piles because authorities can't even agree on the most pressing challenge: clearing the nation's rubbish.

The migration crisis enveloping Europe and much of the Middle East today is one of the worst humanitarian disasters since the 1940s. Millions of desperate people are on the march: Sunni refugees driven out by the barbarity of the Assad regime in Syria, Christians and Yazidis fleeing the pornographic violence of Islamic State, millions more of all faiths and no faith fleeing poverty and oppression without end. Parents are entrusting their lives and the lives of their young children to rickety boats and unscrupulous criminal syndicates along the Mediterranean coast, professionals and business people are giving up their livelihoods and investments, farmers are abandoning their land, and from North Africa to Syria, the sick and the old are on the road, carrying a few treasured belongings on a new trail of tears.

By Andreane Williams,