Is Spain starting to come apart?

Has Ambrose put his finger on one of this week's biggest stories? (In true Ambrose style he includes a short history lesson about 1714, "when Philip V abolished all Catalan institutions, and imposed Castilian laws and absolutism by right of conquest".)

It seems the ruling parties of Catalonia have sought guidance from Brussels on the legality of secession from Spain. This sounds like gesture politics, but both the Catalans and the Spanish government are playing for high stakes.

The Catalans appear to want greater tax autonomy within Spain. The Spanish government says the constitution "allows no margin for compromise", says Ambrose. The Catalan leader Artur Mas succinctly responded

Constitutions may or may not be modified, but they do not subjugate the will of the people.

The Spanish government is trying to reduce the autonomy of the regions. They have borrowed large amounts from international lenders, and several are probably corrupt. Until now Mr Mas had been on careful political manoeuvres, but the Spanish government's policy has caused the political winds to blow up in Barcelona, and Mr Mas is trying to adapt.

The speed of events has caught almost everybody by surprise, including Mr Mas himself. His CiU has, until now, pursued a policy of calculated ambiguity over secession. Mr Mas has pivoted quickly, embracing what he calls the “popular outcry” as his own.

The political stakes are getting higher, and as Ambrose puts it, "the risks of a misjudgement are growing", with an intervention from the King. Not only the King.

A serving army officer, Colonel Francisco Alaman, has fuelled the flames by comparing the crisis with 1936 – when Gen Francisco Franco seized power – and by vowing to crush Catalan nationalists, described as “vultures”.

“Independence for Catalunya? Over my dead body. Spain is not Yugoslavia or Belgium. Even if the lion is sleeping, don’t provoke the lion, because he will show the ferocity proven over centuries,” he said.

Retired Lt-Gen Pedro Pitarch, a former army chief, said the words reflect “deeply-rooted thinking in large parts of the armed forces”. He also accused Madrid of bungling the Catalan drama disastrously.

“Are we looking at a failed state?” he asked

We can be sure that is not what the politicians intended. But can they keep control of events? No one knows yet whether this will turn out to have been just shouting and flag waving.

But against a background of recession and high unemployment, might indignation on the Catalan streets overwhelm politicians who do not appear skilled in compromise?

One to watch.