Migrant crisis: Why do politicians seem unable to act?

"We can't cope!" is the collective cry from across Europe, as the huddled masses spill onto its shores and scramble over hastily-assembled razor wire fences.

"The numbers are too great. It's biblical!"

A little perspective, however, would not go amiss.

This may be Europe's biggest migration crisis since World War Two, but it is nothing compared to the challenges facing neighbouring countries in the Middle East.

Take a look at the numbers in Turkey. In Jordan. In Lebanon.

There are millions of people seeking shelter, in countries that have far fewer resources to help them cope.

And yet so many people want to reach the EU that the system is creaking at the seams, and the limits of European cooperation are being laid bare.

The number of refugees and asylum seekers in Turkey in 2015 is expected to rise to nearly 1.9 million, including 1.7 million Syrian refugees

No-one can fail to be moved by the tragic stories of sinking ships and shattered lives. The gruesome discovery of 71 decomposing bodies locked inside a lorry in Austria is only the latest in a shameful saga.

Politicians say enough is enough. Something must be done. And they mean it.

But for every European who sees an overwhelming moral imperative to act there may be another who wants to close their eyes and wish the migration crisis away.

And there are multiple reasons why EU leaders are struggling to come up with viable solutions.

Anti-immigration sentiment is on the rise in many countries, often fuelled by economic discontent and a sense of a loss of control.

Unique experiment

The scale of this mass movement of people seems to have taken everyone by surprise.

And some of the EU rules that have evolved over the years to cope with migration flows have failed to stand up to scrutiny.

The Dublin regulation for example - which requires asylum seekers to make their applications in the first EU member state they reach - seems designed to play one country off against another.

It is a reminder that the EU is a unique experiment in partially shared sovereignty.

For several years the focus has been on the single currency - now the borderless Schengen area has come into sharp focus as well.

Nowhere else in the world does one external border contain so many countries with so many differing asylum and immigration policies.

And that brings with it a set of challenges that have simply intensified an unsettling sense of a system that is not fit for purpose.

No instant solutions

Has there been a political response?

Of course there has. EU leaders have endorsed a 'migration agenda' put forward by the European Commission.

All talk, say the critics.

The migration crisis dominated the Western Balkans Conference in Vienna

But it includes immediate measures to support countries on the front line that are struggling to deal with asylum claims; it aims to create systems to ensure that far more failed asylum seekers are returned home; and it promises longer term efforts to put people smuggling networks out of business, and to focus on development issues in the Middle East and sub-Saharan Africa.

The trouble with long term plans is that they are long term. They provide no instant solutions. And there will be further unseemly squabbles ahead.

But you have to start somewhere, and as the scale of the migration crisis continues to grow, more European coordination looks inevitable.

Angela Merkel has called this the biggest challenge of her decade in power as Germany's chancellor.

It is both a human tragedy, and a moment of considerable political risk for the European project she supports.