A European prime minister is talking seriously about the EU collapsing like the Roman Empire

In an interview with international news organisations this week, Dutch Prime Minister Mark Rutte suggested that western European states might need to bring in a "mini-Schengen" to deal with the bloc's migrant crisis, referring to the Schenghen Agreement that began the abolition of internal border controls in much of the European Union.

A shrunken agreement to leave internal borders open might, for example, exclude countries in south-eastern Europe. A huge number of refugees have arrived in Europe on boats from Turkey, landing in Greece and attempting to travel north.

He turned that into a more startling analogy, according to a report from the Financial Times. Here's the kicker:

"As we all know from the Roman empire, big empires go down if the borders are not well-protected," said Mr Rutte in an interview with a group of international newspapers. "So we really have an imperative that it is handled."

He's one. His concern is perhaps not unrelated to the fact that Geert Wilders' hard-right and anti-immigration Party of Freedom leads some Dutch political polls by double digits right now.

But Rutte isn't the first or only person to make the analogy. Historian Niall Ferguson made a similar point about the EU and Rome in the aftermath of the Islamist attacks on Paris this month.

Here's a snippet from his op-ed in the Boston Globe:

Let us be clear about what is happening. Like the Roman Empire in the early fifth century, Europe has allowed its defenses to crumble. As its wealth has grown, so its military prowess has shrunk, along with its self-belief. It has grown decadent in its shopping malls and sports stadiums. At the same time, it has opened its gates to outsiders who have coveted its wealth without renouncing their ancestral faith.

The tremendous surge in the number of refugees arriving in Europe is the latest in a series of crises that the bloc has attempted to muddle through in recent years.

From Greece's bailout and the economic turmoil in southern Europe generally, to the heightened security concerns following Russia's invasion of Ukraine, it seems like Europe drifts from one challenge to the next, failing to find a healthy balance between national sovereignty and the need for collective action.