DAKAR, Senegal — The world-turned-upside-down of the European debt crisis reached a new extreme last week when Europe came pleading for lucre where it once only seized it: Africa.

The hands-out visit on Thursday of Prime Minister Pedro Passos Coelho of Portugal to its former colony Angola — once a prime source of slaves, then a dumping ground for the mother country’s human rejects and now swimming in oil wealth — was a milestone of sorts.

While Europe’s financial distress has already revived bad historical memories — 70 years after Nazi occupation, Greeks are grumbling about taking marching orders from German gauleiters — and reversed others — there was talk of a Chinese rescue for the continent that once humiliated it — the Angola-Portugal moment has had no equal in its upfront plaintiveness.

“Angolan capital is very welcome,” Mr. Passos Coelho said in Luanda, the capital city. That may be an understatement: the former colony’s cash could be essential as Portugal is forced to sell off state-owned companies and shutter embassies after a $105 billion International Monetary Fund bailout this year....